diff --git a/easybuild/easyblocks/a/adf.py b/easybuild/easyblocks/a/adf.py
index 634c5d4f81a..7a35f73c889 100644
--- a/easybuild/easyblocks/a/adf.py
+++ b/easybuild/easyblocks/a/adf.py
@@ -80,7 +80,7 @@ def install_step(self):
         except OSError as err:
             raise EasyBuildError("Failed to copy %s to %s: %s", src_init_path, target_init_path, err)
 
-        cmd = "./bin/foray -j %d" % self.cfg['parallel']
+        cmd = f"./bin/foray -j {self.cfg.parallel}"
         run_shell_cmd(cmd)
 
     def sanity_check_step(self):
diff --git a/easybuild/easyblocks/a/aomp.py b/easybuild/easyblocks/a/aomp.py
index 58ab38187ce..99c4673651a 100644
--- a/easybuild/easyblocks/a/aomp.py
+++ b/easybuild/easyblocks/a/aomp.py
@@ -85,11 +85,7 @@ def configure_step(self):
             'AOMP_APPLY_ROCM_PATCHES=0',
             'AOMP_STANDALONE_BUILD=1',
         ]
-        if self.cfg['parallel']:
-            install_options.append(
-                'NUM_THREADS={!s}'.format(self.cfg['parallel']))
-        else:
-            install_options.append('NUM_THREADS=1')
+        install_options.append(f'NUM_THREADS={self.cfg.parallel}')
         # Check if CUDA is loaded and alternatively build CUDA backend
         if get_software_root('CUDA') or get_software_root('CUDAcore'):
             cuda_root = get_software_root('CUDA') or get_software_root('CUDAcore')
diff --git a/easybuild/easyblocks/b/bazel.py b/easybuild/easyblocks/b/bazel.py
index f9269c834e0..e45c6ee605a 100644
--- a/easybuild/easyblocks/b/bazel.py
+++ b/easybuild/easyblocks/b/bazel.py
@@ -158,7 +158,7 @@ def configure_step(self):
         ])
 
         # enable building in parallel
-        bazel_args = '--jobs=%d' % self.cfg['parallel']
+        bazel_args = f'--jobs={self.cfg.parallel}'
 
         # Bazel provides a JDK by itself for some architectures
         # We want to enforce it using the JDK we provided via modules
@@ -206,7 +206,7 @@ def test_step(self):
                 # Avoid bazel using $HOME
                 '--output_user_root=%s' % self.output_user_root,
                 runtest,
-                '--jobs=%d' % self.cfg['parallel'],
+                f'--jobs={self.cfg.parallel}',
                 '--host_javabase=@local_jdk//:jdk',
                 # Be more verbose
                 '--subcommands', '--verbose_failures',
diff --git a/easybuild/easyblocks/b/berkeleygw.py b/easybuild/easyblocks/b/berkeleygw.py
index fb6975a3e0e..b7d28798042 100644
--- a/easybuild/easyblocks/b/berkeleygw.py
+++ b/easybuild/easyblocks/b/berkeleygw.py
@@ -62,7 +62,7 @@ def configure_step(self):
     def build_step(self):
         """Custom build step for BerkeleyGW."""
 
-        self.cfg['parallel'] = 1
+        self.cfg.parallel = 1
 
         self.cfg['buildopts'] = 'all-flavors'
 
diff --git a/easybuild/easyblocks/b/boost.py b/easybuild/easyblocks/b/boost.py
index 5e302152478..e6d3981a829 100644
--- a/easybuild/easyblocks/b/boost.py
+++ b/easybuild/easyblocks/b/boost.py
@@ -227,8 +227,8 @@ def build_step(self):
                 self.bjamoptions += " -s%s_INCLUDE=%s/include" % (lib.upper(), libroot)
                 self.bjamoptions += " -s%s_LIBPATH=%s/lib" % (lib.upper(), libroot)
 
-        if self.cfg['parallel']:
-            self.paracmd = "-j %s" % self.cfg['parallel']
+        if self.cfg.parallel > 1:
+            self.paracmd = f"-j {self.cfg.parallel}"
         else:
             self.paracmd = ''
 
diff --git a/easybuild/easyblocks/c/clang.py b/easybuild/easyblocks/c/clang.py
index 7e677345b46..6c700b08741 100644
--- a/easybuild/easyblocks/c/clang.py
+++ b/easybuild/easyblocks/c/clang.py
@@ -124,7 +124,6 @@ def __init__(self, *args, **kwargs):
         self.llvm_obj_dir_stage1 = None
         self.llvm_obj_dir_stage2 = None
         self.llvm_obj_dir_stage3 = None
-        self.make_parallel_opts = ""
         self.runtime_lib_path = "lib"
 
         # Bypass the .mod file check for GCCcore installs
@@ -404,9 +403,6 @@ def configure_step(self):
 
         self.cfg.update('configopts', '-DLLVM_TARGETS_TO_BUILD="%s"' % ';'.join(build_targets))
 
-        if self.cfg['parallel']:
-            self.make_parallel_opts = "-j %s" % self.cfg['parallel']
-
         # If hwloc is included as a dep, use it in OpenMP runtime for affinity
         hwloc_root = get_software_root('hwloc')
         if hwloc_root:
@@ -554,7 +550,7 @@ def build_with_prev_stage(self, prev_obj, next_obj):
             run_shell_cmd("cmake %s %s" % (' '.join(options), self.llvm_src_dir))
 
         self.log.info("Building")
-        run_shell_cmd("make %s VERBOSE=1" % self.make_parallel_opts)
+        run_shell_cmd(f"make {self.parallel_flag} VERBOSE=1")
 
         # restore $PATH
         setvar('PATH', orig_path)
@@ -581,7 +577,7 @@ def test_step(self):
                 change_dir(self.llvm_obj_dir_stage3)
             else:
                 change_dir(self.llvm_obj_dir_stage1)
-            run_shell_cmd("make %s check-all" % self.make_parallel_opts)
+            run_shell_cmd(f"make {self.parallel_flag} check-all")
 
     def install_step(self):
         """Install stage 3 binaries."""
diff --git a/easybuild/easyblocks/c/cp2k.py b/easybuild/easyblocks/c/cp2k.py
index aa79e89bba9..8251194b100 100644
--- a/easybuild/easyblocks/c/cp2k.py
+++ b/easybuild/easyblocks/c/cp2k.py
@@ -669,18 +669,17 @@ def build_step(self):
             change_dir(makefiles)
 
             # modify makefile for parallel build
-            parallel = self.cfg['parallel']
-            if parallel:
-
+            parallel = self.cfg.parallel
+            if parallel > 1:
                 try:
                     for line in fileinput.input('Makefile', inplace=1, backup='.orig.patchictce'):
-                        line = re.sub(r"^PMAKE\s*=.*$", "PMAKE\t= $(SMAKE) -j %s" % parallel, line)
+                        line = re.sub(r"^PMAKE\s*=.*$", f"PMAKE\t= $(SMAKE) -j {parallel}", line)
                         sys.stdout.write(line)
                 except IOError as err:
                     raise EasyBuildError("Can't modify/write Makefile in %s: %s", makefiles, err)
 
         # update make options with MAKE
-        self.cfg.update('buildopts', 'MAKE="make -j %s"' % self.cfg['parallel'])
+        self.cfg.update('buildopts', f'MAKE="make -j {self.cfg.parallel}"')
 
         # update make options with ARCH and VERSION
         self.cfg.update('buildopts', 'ARCH=%s VERSION=%s' % (self.typearch, self.cfg['type']))
@@ -757,7 +756,7 @@ def test_step(self):
                 self.log.info("No reference output found for regression test, just continuing without it...")
 
             # prefer using 4 cores, since some tests require/prefer square (n^2) numbers or powers of 2 (2^n)
-            test_core_cnt = min(self.cfg['parallel'], 4)
+            test_core_cnt = min(self.cfg.parallel, 4)
             if get_avail_core_count() < test_core_cnt:
                 raise EasyBuildError("Cannot run MPI tests as not enough cores (< %s) are available", test_core_cnt)
             else:
diff --git a/easybuild/easyblocks/d/dm_reverb.py b/easybuild/easyblocks/d/dm_reverb.py
index 225a0e79195..b94ba015f78 100644
--- a/easybuild/easyblocks/d/dm_reverb.py
+++ b/easybuild/easyblocks/d/dm_reverb.py
@@ -91,7 +91,7 @@ def build_step(self, *args, **kwargs):
         # use JDK from EB
         bazel_build_opts += " --host_javabase=@local_jdk//:jdk"
         # explicitly set the number of processes
-        bazel_build_opts += " --jobs=%d" % self.cfg['parallel']
+        bazel_build_opts += f" --jobs={self.cfg.parallel}"
         # print full compilation commands
         bazel_build_opts += " --subcommands"
 
diff --git a/easybuild/easyblocks/f/flook.py b/easybuild/easyblocks/f/flook.py
index 987f979ad86..93c9b047f92 100644
--- a/easybuild/easyblocks/f/flook.py
+++ b/easybuild/easyblocks/f/flook.py
@@ -55,7 +55,7 @@ def __init__(self, *args, **kwargs):
         else:
             local_comp_flags = 'FFLAGS="$FFLAGS" CFLAGS="$CFLAGS"'
         self.cfg.update('buildopts', 'liball %s' % local_comp_flags)
-        self.cfg['parallel'] = 1
+        self.cfg.parallel = 1
 
     def configure_step(self):
         # flook has no configure step
diff --git a/easybuild/easyblocks/g/gamess_us.py b/easybuild/easyblocks/g/gamess_us.py
index 2d879382630..a1717d448de 100644
--- a/easybuild/easyblocks/g/gamess_us.py
+++ b/easybuild/easyblocks/g/gamess_us.py
@@ -427,11 +427,11 @@ def test_step(self):
                     return
 
                 # MPI builds can only run tests that support parallel execution
-                if int(self.cfg['parallel']) < 2:
+                if self.cfg.parallel < 2:
                     self.log.info("Skipping testing of GAMESS-US as MPI tests need at least 2 CPU cores to run")
                     return
 
-                test_procs = str(self.cfg['parallel'])
+                test_procs = str(self.cfg.parallel)
                 target_tests = [exam for exam in target_tests if exam[0] not in GAMESS_SERIAL_TESTS]
 
                 if self.toolchain.mpi_family() == toolchain.INTELMPI:
diff --git a/easybuild/easyblocks/g/gcc.py b/easybuild/easyblocks/g/gcc.py
index d4e207ef657..4e120fbaae1 100644
--- a/easybuild/easyblocks/g/gcc.py
+++ b/easybuild/easyblocks/g/gcc.py
@@ -741,8 +741,8 @@ def build_step(self):
 
             # make and install stage 1 build of GCC
             paracmd = ''
-            if self.cfg['parallel']:
-                paracmd = "-j %s" % self.cfg['parallel']
+            if self.cfg.parallel > 1:
+                paracmd = f"-j {self.cfg.parallel}"
 
             cmd = "%s make %s %s" % (self.cfg['prebuildopts'], paracmd, self.cfg['buildopts'])
             run_shell_cmd(cmd)
diff --git a/easybuild/easyblocks/g/gromacs.py b/easybuild/easyblocks/g/gromacs.py
index 6e078a6851e..a11b9ba16a0 100644
--- a/easybuild/easyblocks/g/gromacs.py
+++ b/easybuild/easyblocks/g/gromacs.py
@@ -299,12 +299,12 @@ def configure_step(self):
                 mpi_numprocs = self.cfg.get('mpi_numprocs', 0)
                 if mpi_numprocs == 0:
                     self.log.info("No number of test MPI tasks specified -- using default: %s",
-                                  self.cfg['parallel'])
-                    mpi_numprocs = self.cfg['parallel']
+                                  self.cfg.parallel)
+                    mpi_numprocs = self.cfg.parallel
 
-                elif mpi_numprocs > self.cfg['parallel']:
+                elif mpi_numprocs > self.cfg.parallel:
                     self.log.warning("Number of test MPI tasks (%s) is greater than value for 'parallel': %s",
-                                     mpi_numprocs, self.cfg['parallel'])
+                                     mpi_numprocs, self.cfg.parallel)
 
                 mpiexec = self.cfg.get('mpiexec')
                 if mpiexec:
@@ -511,7 +511,7 @@ def test_step(self):
 
                 # run 'make check' or whatever the easyconfig specifies
                 # in parallel since it involves more compilation
-                self.cfg.update('runtest', "-j %s" % self.cfg['parallel'])
+                self.cfg.update('runtest', f"-j {self.cfg.parallel}")
                 super(EB_GROMACS, self).test_step()
 
                 if build_option('rpath'):
@@ -535,7 +535,7 @@ def install_step(self):
             self.log.info("skipping install step")
         else:
             # run 'make install' in parallel since it involves more compilation
-            self.cfg.update('installopts', "-j %s" % self.cfg['parallel'])
+            self.cfg.update('installopts', f"-j {self.cfg.parallel}")
             super(EB_GROMACS, self).install_step()
 
     def extensions_step(self, fetch=False):
diff --git a/easybuild/easyblocks/generic/cargo.py b/easybuild/easyblocks/generic/cargo.py
index 4b3d9132ed5..89401365fd8 100644
--- a/easybuild/easyblocks/generic/cargo.py
+++ b/easybuild/easyblocks/generic/cargo.py
@@ -356,8 +356,8 @@ def profile(self):
     def build_step(self):
         """Build with cargo"""
         parallel = ''
-        if self.cfg['parallel']:
-            parallel = "-j %s" % self.cfg['parallel']
+        if self.cfg.parallel > 1:
+            parallel = f"-j {self.cfg.parallel}"
 
         tests = ''
         if self.cfg['enable_tests']:
diff --git a/easybuild/easyblocks/generic/configuremake.py b/easybuild/easyblocks/generic/configuremake.py
index e00941fd80b..408595ac467 100644
--- a/easybuild/easyblocks/generic/configuremake.py
+++ b/easybuild/easyblocks/generic/configuremake.py
@@ -210,6 +210,11 @@ def __init__(self, *args, **kwargs):
 
         self.config_guess = None
 
+    @property
+    def parallel_flag(self):
+        """Return the flag to enable parallelism or empty for serial"""
+        return f'-j {self.cfg.parallel}' if self.cfg.parallel > 1 else ''
+
     def obtain_config_guess(self, download_source_path=None, search_source_paths=None):
         """
         Locate or download an up-to-date config.guess for use with ConfigureMake
@@ -360,10 +365,6 @@ def build_step(self, verbose=None, path=None):
         if verbose is not None:
             self.log.deprecated("The 'verbose' parameter to build_step is deprecated and unneeded.", '6.0')
 
-        paracmd = ''
-        if self.cfg['parallel']:
-            paracmd = "-j %s" % self.cfg['parallel']
-
         targets = self.cfg.get('build_cmd_targets') or DEFAULT_BUILD_TARGET
         # ensure strings are converted to list
         targets = [targets] if isinstance(targets, str) else targets
@@ -373,7 +374,7 @@ def build_step(self, verbose=None, path=None):
                 self.cfg['prebuildopts'],
                 self.cfg.get('build_cmd') or DEFAULT_BUILD_CMD,
                 target,
-                paracmd,
+                self.parallel_flag,
                 self.cfg['buildopts'],
             ])
             self.log.info("Building target '%s'", target)
diff --git a/easybuild/easyblocks/generic/mesonninja.py b/easybuild/easyblocks/generic/mesonninja.py
index 495beef7f35..22bf6ae68eb 100644
--- a/easybuild/easyblocks/generic/mesonninja.py
+++ b/easybuild/easyblocks/generic/mesonninja.py
@@ -136,9 +136,7 @@ def build_step(self, verbose=False, path=None):
         """
         build_cmd = self.cfg.get('build_cmd', DEFAULT_BUILD_CMD)
 
-        parallel = ''
-        if self.cfg['parallel']:
-            parallel = "-j %s" % self.cfg['parallel']
+        parallel = f'-j {self.cfg.parallel}' if self.cfg.parallel > 1 else ''
 
         cmd = "%(prebuildopts)s %(build_cmd)s -v %(parallel)s %(buildopts)s" % {
             'buildopts': self.cfg['buildopts'],
@@ -164,9 +162,7 @@ def install_step(self):
         """
         install_cmd = self.cfg.get('install_cmd', DEFAULT_INSTALL_CMD)
 
-        parallel = ''
-        if self.cfg['parallel']:
-            parallel = "-j %s" % self.cfg['parallel']
+        parallel = f'-j {self.cfg.parallel}' if self.cfg.parallel > 1 else ''
 
         cmd = "%(preinstallopts)s %(install_cmd)s %(parallel)s %(installopts)s install" % {
             'installopts': self.cfg['installopts'],
diff --git a/easybuild/easyblocks/generic/scons.py b/easybuild/easyblocks/generic/scons.py
index 526f7e52b6e..88c55222dee 100644
--- a/easybuild/easyblocks/generic/scons.py
+++ b/easybuild/easyblocks/generic/scons.py
@@ -56,9 +56,7 @@ def build_step(self, verbose=False):
         Build with SCons
         """
 
-        par = ''
-        if self.cfg['parallel']:
-            par = "-j %s" % self.cfg['parallel']
+        par = f'-j {self.cfg.parallel}' if self.cfg.parallel > 1 else ''
 
         cmd = "%(prebuildopts)s scons %(par)s %(buildopts)s %(prefix)s" % {
             'buildopts': self.cfg['buildopts'],
diff --git a/easybuild/easyblocks/h/hadoop.py b/easybuild/easyblocks/h/hadoop.py
index 376b5e4f2f7..b1162f828dd 100644
--- a/easybuild/easyblocks/h/hadoop.py
+++ b/easybuild/easyblocks/h/hadoop.py
@@ -64,8 +64,8 @@ def build_step(self):
                     raise EasyBuildError("%s not found. Failing install" % native_lib)
                 cmd += ' -Drequire.%s=true -D%s.prefix=%s' % (native_lib, native_lib, lib_root)
 
-            if self.cfg['parallel'] > 1:
-                cmd += " -T%d" % self.cfg['parallel']
+            if self.cfg.parallel > 1:
+                cmd += f" -T{self.cfg.parallel}"
             run_shell_cmd(cmd)
 
     def install_step(self):
diff --git a/easybuild/easyblocks/i/impi.py b/easybuild/easyblocks/i/impi.py
index b2d80c028cb..d210b48e758 100644
--- a/easybuild/easyblocks/i/impi.py
+++ b/easybuild/easyblocks/i/impi.py
@@ -106,8 +106,8 @@ def install_step(self):
                     libfabric_installpath = os.path.join(self.installdir, 'intel64', 'libfabric')
 
                     make = 'make'
-                    if self.cfg['parallel']:
-                        make += ' -j %d' % self.cfg['parallel']
+                    if self.cfg.parallel > 1:
+                        make += f' -j {self.cfg.parallel}'
 
                     cmds = [
                         f"./configure --prefix={libfabric_installpath} {self.cfg['libfabric_configopts']}",
@@ -217,7 +217,7 @@ def sanity_check_step(self):
             build_cmd = "mpicc -cc=%s %s -o %s" % (os.getenv('CC'), impi_testsrc, impi_testexe)
 
             # Execute test program with appropriate MPI executable for target toolchain
-            params = {'nr_ranks': self.cfg['parallel'], 'cmd': impi_testexe}
+            params = {'nr_ranks': self.cfg.parallel, 'cmd': impi_testexe}
             mpi_cmd_tmpl, params = get_mpi_cmd_template(toolchain.INTELMPI, params, mpi_version=self.version)
 
             custom_commands.extend([
diff --git a/easybuild/easyblocks/j/jaxlib.py b/easybuild/easyblocks/j/jaxlib.py
index 2ddf4a2996b..e876258b089 100644
--- a/easybuild/easyblocks/j/jaxlib.py
+++ b/easybuild/easyblocks/j/jaxlib.py
@@ -88,7 +88,7 @@ def configure_step(self):
 
         # Passed to the build command of bazel
         bazel_options = [
-            '--jobs=%s' % self.cfg['parallel'],
+            f'--jobs={self.cfg.parallel}',
             '--subcommands',
             '--action_env=PYTHONPATH',
             '--action_env=EBPYTHONPREFIXES',
diff --git a/easybuild/easyblocks/m/molpro.py b/easybuild/easyblocks/m/molpro.py
index c9e7a3b3264..fbeeab78e6d 100644
--- a/easybuild/easyblocks/m/molpro.py
+++ b/easybuild/easyblocks/m/molpro.py
@@ -157,8 +157,8 @@ def configure_step(self):
 
             # determine MPI launcher command that can be used during build/test
             # obtain command with specific number of cores (required by mpi_cmd_for), then replace that number with '%n'
-            launcher = self.toolchain.mpi_cmd_for('%x', self.cfg['parallel'])
-            launcher = launcher.replace(' %s' % self.cfg['parallel'], ' %n')
+            launcher = self.toolchain.mpi_cmd_for('%x', self.cfg.parallel)
+            launcher = launcher.replace(f' {self.cfg.parallel}', ' %n')
 
             # patch CONFIG file to change LAUNCHER definition, in order to avoid having to start mpd
             apply_regex_substitutions(cfgfile, [(r"^(LAUNCHER\s*=\s*).*$", r"\1 %s" % launcher)])
@@ -186,7 +186,7 @@ def test_step(self):
 
             if build_option('mpi_tests'):
                 # extensive test
-                run_shell_cmd("make MOLPRO_OPTIONS='-n%s' test" % self.cfg['parallel'])
+                run_shell_cmd(f"make MOLPRO_OPTIONS='-n{self.cfg.parallel}' test")
             else:
                 self.log.info("Skipping extensive testing of Molpro since MPI testing is disabled")
 
diff --git a/easybuild/easyblocks/m/mrtrix.py b/easybuild/easyblocks/m/mrtrix.py
index 45ab32fb549..df978077f87 100644
--- a/easybuild/easyblocks/m/mrtrix.py
+++ b/easybuild/easyblocks/m/mrtrix.py
@@ -74,8 +74,7 @@ def configure_step(self):
 
     def build_step(self):
         """Custom build procedure for MRtrix."""
-        parallel = self.cfg['parallel']
-        env.setvar('NUMBER_OF_PROCESSORS', str(parallel))
+        env.setvar('NUMBER_OF_PROCESSORS', str(self.cfg.parallel))
 
         cmd = "python build -verbose"
         run_shell_cmd(cmd)
diff --git a/easybuild/easyblocks/n/namd.py b/easybuild/easyblocks/n/namd.py
index 36cb2f13247..ae89f349835 100644
--- a/easybuild/easyblocks/n/namd.py
+++ b/easybuild/easyblocks/n/namd.py
@@ -147,7 +147,7 @@ def configure_step(self):
             'arch': self.cfg['charm_arch'],
             'cxxflags': os.environ['CXXFLAGS'] + ' -DMPICH_IGNORE_CXX_SEEK ' + self.cfg['charm_extra_cxxflags'],
             'opts': self.cfg['charm_opts'],
-            'parallel': self.cfg['parallel'],
+            'parallel': self.cfg.parallel,
         }
         charm_subdir = '.'.join(os.path.basename(self.charm_tarballs[0]).split('.')[:-1])
         self.log.debug("Building Charm++ using cmd '%s' in '%s'" % (cmd, charm_subdir))
diff --git a/easybuild/easyblocks/n/neuron.py b/easybuild/easyblocks/n/neuron.py
index 436d138a572..8c2c4c83c3b 100644
--- a/easybuild/easyblocks/n/neuron.py
+++ b/easybuild/easyblocks/n/neuron.py
@@ -105,7 +105,7 @@ def configure_step(self):
     def test_step(self):
         """Custom tests for NEURON."""
         if build_option('mpi_tests'):
-            nproc = self.cfg['parallel']
+            nproc = self.cfg.parallel
             try:
                 hoc_file = os.path.join(self.cfg['start_dir'], 'src', 'parallel', 'test0.hoc')
                 cmd = self.toolchain.mpi_cmd_for(f"bin/nrniv -mpi {hoc_file}", nproc)
diff --git a/easybuild/easyblocks/n/nwchem.py b/easybuild/easyblocks/n/nwchem.py
index fc7962d0c82..11189ea0295 100644
--- a/easybuild/easyblocks/n/nwchem.py
+++ b/easybuild/easyblocks/n/nwchem.py
@@ -276,8 +276,8 @@ def build_step(self):
 
         # check whether 64-bit integers should be used, and act on it
         if not self.toolchain.options['i8']:
-            if self.cfg['parallel']:
-                self.cfg.update('buildopts', '-j %s' % self.cfg['parallel'])
+            if self.parallel_flag:
+                self.cfg.update('buildopts', self.parallel_flag)
             run_shell_cmd("make %s 64_to_32" % self.cfg['buildopts'])
 
             self.setvar_env_makeopt('USE_64TO32', "y")
diff --git a/easybuild/easyblocks/o/openblas.py b/easybuild/easyblocks/o/openblas.py
index cb6a4ce75a1..3f6ab39db30 100644
--- a/easybuild/easyblocks/o/openblas.py
+++ b/easybuild/easyblocks/o/openblas.py
@@ -105,9 +105,7 @@ def build_step(self):
             del os.environ[cflags]
             self.log.info("Environment variable %s unset and passed through command line" % cflags)
 
-        makecmd = 'make'
-        if self.cfg['parallel']:
-            makecmd += ' -j %s' % self.cfg['parallel']
+        makecmd = f'make {self.parallel_flag}'
 
         cmd = ' '.join([self.cfg['prebuildopts'], makecmd, ' '.join(build_parts), self.cfg['buildopts']])
         run_shell_cmd(cmd)
diff --git a/easybuild/easyblocks/o/openfoam.py b/easybuild/easyblocks/o/openfoam.py
index 2d9ef6cae4b..641165a604f 100644
--- a/easybuild/easyblocks/o/openfoam.py
+++ b/easybuild/easyblocks/o/openfoam.py
@@ -271,7 +271,7 @@ def configure_step(self):
         env.setvar("WM_COMPILE_OPTION", self.build_type)
 
         # parallel build spec
-        env.setvar("WM_NCOMPPROCS", str(self.cfg['parallel']))
+        env.setvar("WM_NCOMPPROCS", str(self.cfg.parallel))
 
         # OpenFOAM >= 3.0.0 can use 64 bit integers
         if not self.is_extend and self.looseversion >= LooseVersion('3.0'):
diff --git a/easybuild/easyblocks/o/openmpi.py b/easybuild/easyblocks/o/openmpi.py
index 55128d389f5..44dc9e1aa22 100644
--- a/easybuild/easyblocks/o/openmpi.py
+++ b/easybuild/easyblocks/o/openmpi.py
@@ -219,7 +219,7 @@ def sanity_check_step(self):
         # Run with correct MPI launcher
         mpi_cmd_tmpl, params = get_mpi_cmd_template(toolchain.OPENMPI, dict(), mpi_version=self.version)
         # Limit number of ranks to 8 to avoid it failing due to hyperthreading
-        ranks = min(8, self.cfg['parallel'])
+        ranks = min(8, self.cfg.parallel)
         for srcdir, src, compiler in (
             ('examples', 'hello_c.c', 'mpicc'),
             ('examples', 'hello_mpifh.f', 'mpifort'),
diff --git a/easybuild/easyblocks/p/parmetis.py b/easybuild/easyblocks/p/parmetis.py
index 85b076746d5..1b6d5a20b4f 100644
--- a/easybuild/easyblocks/p/parmetis.py
+++ b/easybuild/easyblocks/p/parmetis.py
@@ -102,9 +102,7 @@ def configure_step(self):
     def build_step(self):
         """Build ParMETIS (and METIS) using build_step."""
 
-        paracmd = ''
-        if self.cfg['parallel']:
-            paracmd = "-j %s" % self.cfg['parallel']
+        paracmd = f'-j {self.cfg.parallel}' if self.cfg.parallel > 1 else ''
 
         self.cfg.update('buildopts', 'LIBDIR=""')
 
diff --git a/easybuild/easyblocks/p/pdt.py b/easybuild/easyblocks/p/pdt.py
index 1fbc109e2f5..d839f0f2213 100644
--- a/easybuild/easyblocks/p/pdt.py
+++ b/easybuild/easyblocks/p/pdt.py
@@ -98,8 +98,8 @@ def make_installdir(self):
     def install_step(self):
         """Create symlinks into arch-specific directories"""
 
-        if self.cfg['parallel']:
-            self.cfg.update('installopts', '-j %s' % self.cfg['parallel'])
+        if self.parallel_flag:
+            self.cfg.update('installopts', self.parallel_flag)
 
         super(EB_PDT, self).install_step()
 
diff --git a/easybuild/easyblocks/p/perl.py b/easybuild/easyblocks/p/perl.py
index 729a84db172..9e70f5e2a0d 100644
--- a/easybuild/easyblocks/p/perl.py
+++ b/easybuild/easyblocks/p/perl.py
@@ -122,17 +122,13 @@ def test_step(self):
         """Test Perl build via 'make test'."""
         # allow escaping with runtest = False
         if self.cfg['runtest'] is None or self.cfg['runtest']:
-            parallel = self.cfg['parallel']
+            parallel = self.cfg.parallel
             if isinstance(self.cfg['runtest'], str):
                 cmd = "make %s" % self.cfg['runtest']
-            elif parallel and LooseVersion(self.version) >= LooseVersion('5.30.0'):
+            elif parallel > 1 and LooseVersion(self.version) >= LooseVersion('5.30.0'):
                 # run tests in parallel, see https://perldoc.perl.org/perlhack#Parallel-tests;
                 # only do this for Perl 5.30 and newer (conservative choice, actually supported in Perl >= 5.10.1)
-                cmd = ' '.join([
-                    'TEST_JOBS=%s' % parallel,
-                    'PERL_TEST_HARNESS_ASAP=1',
-                    "make -j %s test_harness" % parallel,
-                ])
+                cmd = f'TEST_JOBS={parallel} PERL_TEST_HARNESS_ASAP=1 make -j {parallel} test_harness',
             else:
                 cmd = "make test"
 
diff --git a/easybuild/easyblocks/p/petsc.py b/easybuild/easyblocks/p/petsc.py
index 673983e4fce..2a3ee9b4a4f 100644
--- a/easybuild/easyblocks/p/petsc.py
+++ b/easybuild/easyblocks/p/petsc.py
@@ -193,7 +193,7 @@ def configure_step(self):
             self.cfg.update('configopts', '--with-mpi=1')
 
         # build options
-        self.cfg.update('configopts', '--with-build-step-np=%s' % self.cfg['parallel'])
+        self.cfg.update('configopts', f'--with-build-step-np={self.cfg.parallel}')
         self.cfg.update('configopts', '--with-shared-libraries=%d' % self.cfg['shared_libs'])
         self.cfg.update('configopts', '--with-debugging=%d' % self.toolchain.options['debug'])
         self.cfg.update('configopts', '--with-pic=%d' % self.toolchain.options['pic'])
@@ -348,14 +348,14 @@ def configure_step(self):
             else:
                 raise EasyBuildError("Failed to determine PETSC_ARCH setting.")
 
-        # Make sure to set test_parallel before self.cfg['parallel'] is set to None
-        if self.cfg['test_parallel'] is None and self.cfg['parallel']:
-            self.cfg['test_parallel'] = self.cfg['parallel']
+        # Make sure to set test_parallel before self.cfg.parallel is set to 1
+        if self.cfg['test_parallel'] is None:
+            self.cfg['test_parallel'] = self.cfg.parallel
 
         # PETSc make does not accept -j
         # to control parallel build, we need to specify MAKE_NP=... as argument to 'make' command
-        self.cfg.update('buildopts', "MAKE_NP=%s" % self.cfg['parallel'])
-        self.cfg['parallel'] = None
+        self.cfg.update('buildopts', f"MAKE_NP={self.cfg.parallel}")
+        self.cfg.parallel = 1
 
     # default make should be fine
 
@@ -364,13 +364,13 @@ def test_step(self):
         Test the compilation
         """
 
-        # Each PETSc test may use multiple threads, so running "self.cfg['parallel']" of them may lead to
+        # Each PETSc test may use multiple threads, so running "self.cfg.parallel" of them may lead to
         # some oversubscription every now and again. Not a big deal, but if needed a reduced parallelism
         # can be specified with test_parallel - and it takes priority
         paracmd = ''
         self.log.info("In test_step: %s" % self.cfg['test_parallel'])
-        if self.cfg['test_parallel'] is not None:
-            paracmd = "-j %s" % self.cfg['test_parallel']
+        if self.cfg['test_parallel'] > 1:
+            paracmd = f"-j {self.cfg['test_parallel']}"
 
         if self.cfg['runtest']:
             cmd = "%s make %s %s %s" % (self.cfg['pretestopts'], paracmd, self.cfg['runtest'], self.cfg['testopts'])
diff --git a/easybuild/easyblocks/p/psi.py b/easybuild/easyblocks/p/psi.py
index feddbecb82a..1b558fe51db 100644
--- a/easybuild/easyblocks/p/psi.py
+++ b/easybuild/easyblocks/p/psi.py
@@ -218,11 +218,8 @@ def test_step(self):
             if self.cfg['runtest']:
                 paracmd = ''
                 # Run ctest parallel, but limit to maximum 4 jobs (in case of slow disks)
-                if self.cfg['parallel']:
-                    if self.cfg['parallel'] > 4:
-                        paracmd = '-j 4'
-                    else:
-                        paracmd = "-j %s" % self.cfg['parallel']
+                if self.cfg.parallel > 1:
+                    paracmd = f"-j {min(4, self.cfg.parallel)}"
                 cmd = "ctest %s %s" % (paracmd, self.cfg['runtest'])
                 run_shell_cmd(cmd)
         else:
diff --git a/easybuild/easyblocks/p/pytorch.py b/easybuild/easyblocks/p/pytorch.py
index c70aa2237f6..4795f91c52e 100644
--- a/easybuild/easyblocks/p/pytorch.py
+++ b/easybuild/easyblocks/p/pytorch.py
@@ -338,7 +338,7 @@ def add_enable_option(name, enabled):
         add_enable_option('VERBOSE', build_option('debug'))
 
         # Restrict parallelism
-        options.append('MAX_JOBS=%s' % self.cfg['parallel'])
+        options.append(f'MAX_JOBS={self.cfg.parallel}')
 
         # BLAS Interface
         if get_software_root('imkl'):
diff --git a/easybuild/easyblocks/q/qt.py b/easybuild/easyblocks/q/qt.py
index bd00280b302..e12fd4a30a5 100644
--- a/easybuild/easyblocks/q/qt.py
+++ b/easybuild/easyblocks/q/qt.py
@@ -161,7 +161,7 @@ def configure_step(self):
         # note that $NINJAFLAGS is not a generic thing for Ninja, it's very specific to the Qt5 build procedure
         if LooseVersion(self.version) >= LooseVersion('5'):
             if get_software_root('Ninja'):
-                env.setvar('NINJAFLAGS', '-j%s' % self.cfg['parallel'])
+                env.setvar('NINJAFLAGS', self.parallel_flag)
 
     def build_step(self):
         """Set $LD_LIBRARY_PATH before calling make, to ensure that all required libraries are found during linking."""
diff --git a/easybuild/easyblocks/q/quantumespresso.py b/easybuild/easyblocks/q/quantumespresso.py
index 9aa53ccd249..3178c25ff2c 100644
--- a/easybuild/easyblocks/q/quantumespresso.py
+++ b/easybuild/easyblocks/q/quantumespresso.py
@@ -356,14 +356,10 @@ def test_step(self):
                 return
 
             thr = self.cfg.get('test_suite_threshold', 0.97)
-            concurrent = max(1, self.cfg.get('parallel', 1) // self._test_nprocs)
+            concurrent = max(1, self.cfg.parallel // self._test_nprocs)
             allow_fail = self.cfg.get('test_suite_allow_failures', [])
 
-            cmd = ' '.join([
-                'ctest',
-                '-j%d' % concurrent,
-                '--output-on-failure',
-            ])
+            cmd = f'ctest -j{concurrent} --output-on-failure'
 
             res = run_shell_cmd(cmd, fail_on_error=False)
             out = res.output
diff --git a/easybuild/easyblocks/r/rosetta.py b/easybuild/easyblocks/r/rosetta.py
index 139cce039c3..f628b878e59 100644
--- a/easybuild/easyblocks/r/rosetta.py
+++ b/easybuild/easyblocks/r/rosetta.py
@@ -182,9 +182,7 @@ def build_step(self):
             os.chdir(self.srcdir)
         except OSError as err:
             raise EasyBuildError("Failed to change to %s: %s", self.srcdir, err)
-        par = ''
-        if self.cfg['parallel']:
-            par = "-j %s" % self.cfg['parallel']
+        par = f"-j {self.cfg.parallel}" if self.cfg.parallel > 1 else ""
         cmd = "python ./scons.py %s %s bin" % (self.cfg['buildopts'], par)
         run_shell_cmd(cmd)
 
diff --git a/easybuild/easyblocks/s/scalapack.py b/easybuild/easyblocks/s/scalapack.py
index 703bf1f06b2..9e58568cdf4 100644
--- a/easybuild/easyblocks/s/scalapack.py
+++ b/easybuild/easyblocks/s/scalapack.py
@@ -177,12 +177,7 @@ def build_libscalapack_make(self):
         self.cfg.update('buildopts', 'lib')
         self.cfg.update('buildopts', ' '.join(extra_makeopts))
 
-        # Copied from ConfigureMake easyblock
-        paracmd = ''
-        if self.cfg['parallel']:
-            paracmd = "-j %s" % self.cfg['parallel']
-
-        cmd = "%s make %s %s" % (self.cfg['prebuildopts'], paracmd, self.cfg['buildopts'])
+        cmd = "%s make %s %s" % (self.cfg['prebuildopts'], self.parallel_flag, self.cfg['buildopts'])
 
         # Ignore exit code for parallel run
         run_shell_cmd(cmd, fail_on_error=False)
@@ -192,7 +187,7 @@ def build_libscalapack_make(self):
         self.cfg.update('buildopts', ' '.join(extra_makeopts))
 
         remove_file('libscalapack.a')
-        self.cfg['parallel'] = 1
+        self.cfg.parallel = 1
 
     def build_step(self):
         """Build ScaLAPACK using make after setting make options."""
diff --git a/easybuild/easyblocks/s/scipy.py b/easybuild/easyblocks/s/scipy.py
index 86217467a63..48728842b3f 100644
--- a/easybuild/easyblocks/s/scipy.py
+++ b/easybuild/easyblocks/s/scipy.py
@@ -189,7 +189,7 @@ def test_step(self):
                 'python': self.python_cmd,
                 'srcdir': self.cfg['start_dir'],
                 'installdir': tmp_installdir,
-                'parallel': self.cfg['parallel'],
+                'parallel': self.cfg.parallel,
             }
 
             MesonNinja.test_step(self)
@@ -199,7 +199,7 @@ def test_step(self):
                 'python': '%(python)s',
                 'srcdir': self.cfg['start_dir'],
                 'installdir': '',
-                'parallel': self.cfg['parallel'],
+                'parallel': self.cfg.parallel,
             }
             FortranPythonPackage.test_step(self)
 
diff --git a/easybuild/easyblocks/s/siesta.py b/easybuild/easyblocks/s/siesta.py
index 663fb9489a6..3fb167f1cb9 100644
--- a/easybuild/easyblocks/s/siesta.py
+++ b/easybuild/easyblocks/s/siesta.py
@@ -76,7 +76,7 @@ def configure_step(self):
 
         par = ''
         if loose_ver >= LooseVersion('4.1'):
-            par = '-j %s' % self.cfg['parallel']
+            par = f"-j {self.cfg.parallel}"
 
         # enable OpenMP support if desired
         env_var_suff = ''
diff --git a/easybuild/easyblocks/s/slepc.py b/easybuild/easyblocks/s/slepc.py
index 47afde86d42..1f663c1a43e 100644
--- a/easybuild/easyblocks/s/slepc.py
+++ b/easybuild/easyblocks/s/slepc.py
@@ -129,7 +129,7 @@ def configure_step(self):
 
         # SLEPc > 3.5, make does not accept -j
         if LooseVersion(self.version) >= LooseVersion("3.5"):
-            self.cfg['parallel'] = None
+            self.cfg.parallel = 1
 
     def install_step(self):
         """
diff --git a/easybuild/easyblocks/t/tensorflow.py b/easybuild/easyblocks/t/tensorflow.py
index 8cc7122d320..67b1e7ee5c0 100644
--- a/easybuild/easyblocks/t/tensorflow.py
+++ b/easybuild/easyblocks/t/tensorflow.py
@@ -473,7 +473,7 @@ def configure_step(self):
         if self.cfg['maxparallel'] is None:
             # Seemingly Bazel around 3.x got better, so double the max there
             bazel_max = 64 if get_bazel_version() < '3.0.0' else 128
-            self.cfg['parallel'] = min(self.cfg['parallel'], bazel_max)
+            self.cfg.parallel = min(self.cfg.parallel, bazel_max)
 
         # determine location where binutils' ld command is installed
         # note that this may be an RPATH wrapper script (when EasyBuild is configured with --rpath)
@@ -867,7 +867,7 @@ def build_step(self):
         # https://docs.bazel.build/versions/master/user-manual.html#flag--verbose_failures
         self.target_opts.extend(['--subcommands', '--verbose_failures'])
 
-        self.target_opts.append('--jobs=%s' % self.cfg['parallel'])
+        self.target_opts.append(f'--jobs={self.cfg.parallel}')
 
         if self.toolchain.options.get('pic', None):
             self.target_opts.append('--copt="-fPIC"')
@@ -989,7 +989,7 @@ def test_step(self):
         test_opts.append('--build_tests_only')  # Don't build tests which won't be executed
 
         # determine number of cores/GPUs to use for tests
-        max_num_test_jobs = int(self.cfg['test_max_parallel'] or self.cfg['parallel'])
+        max_num_test_jobs = self.cfg['test_max_parallel'] or self.cfg.parallel
         if self._with_cuda:
             if not which('nvidia-smi', on_error=IGNORE):
                 print_warning('Could not find nvidia-smi. Assuming a system without GPUs and skipping GPU tests!')
diff --git a/easybuild/easyblocks/t/tensorflow_compression.py b/easybuild/easyblocks/t/tensorflow_compression.py
index 45b4c96384e..436f1b03cf8 100644
--- a/easybuild/easyblocks/t/tensorflow_compression.py
+++ b/easybuild/easyblocks/t/tensorflow_compression.py
@@ -85,7 +85,7 @@ def build_step(self):
         # https://docs.bazel.build/versions/master/user-manual.html#flag--verbose_failures
         self.target_opts.extend(['--subcommands', '--verbose_failures'])
 
-        self.target_opts.append('--jobs=%s' % self.cfg['parallel'])
+        self.target_opts.append(f'--jobs={self.cfg.parallel}')
 
         # include install location of Python packages in $PYTHONPATH,
         # and specify that value of $PYTHONPATH should be passed down into Bazel build environment,
diff --git a/easybuild/easyblocks/w/wrf.py b/easybuild/easyblocks/w/wrf.py
index e34ae41dcac..77f6c1b2d33 100644
--- a/easybuild/easyblocks/w/wrf.py
+++ b/easybuild/easyblocks/w/wrf.py
@@ -252,10 +252,7 @@ def build_step(self):
         """Build and install WRF and testcases using provided compile script."""
 
         # enable parallel build
-        par = self.cfg['parallel']
-        self.par = ''
-        if par:
-            self.par = "-j %s" % par
+        self.par = f'-j {self.cfg.parallel}' if self.cfg.parallel else ''
 
         # fix compile script shebang to use provided tcsh
         cmpscript = os.path.join(self.start_dir, 'compile')
@@ -328,7 +325,7 @@ def test_step(self):
             # determine number of MPI ranks to use in tests (1/2 of available processors + 1);
             # we need to limit max number of MPI ranks (8 is too high for some tests, 4 is OK),
             # since otherwise run may fail because domain size is too small
-            n_mpi_ranks = min(self.cfg['parallel'] // 2 + 1, 4)
+            n_mpi_ranks = min(self.cfg.parallel // 2 + 1, 4)
 
             # prepare run command