diff --git a/src/kontrol/foundry.py b/src/kontrol/foundry.py
index 1dbb4f92f..56d7c4e33 100644
--- a/src/kontrol/foundry.py
+++ b/src/kontrol/foundry.py
@@ -21,14 +21,22 @@
 from kevm_pyk.utils import byte_offset_to_lines, legacy_explore, print_failure_info, print_model
 from pyk.cterm import CTerm
 from pyk.kast.inner import KApply, KInner, KSort, KToken, KVariable
-from pyk.kast.manip import cell_label_to_var_name, collect, extract_lhs, flatten_label, minimize_term, top_down
+from pyk.kast.manip import (
+    cell_label_to_var_name,
+    collect,
+    extract_lhs,
+    flatten_label,
+    minimize_term,
+    ml_pred_to_bool,
+    top_down,
+)
 from pyk.kast.outer import KDefinition, KFlatModule, KImport, KRequire
 from pyk.kcfg import KCFG
 from pyk.kcfg.minimize import KCFGMinimizer
 from pyk.prelude.bytes import bytesToken
 from pyk.prelude.collections import map_empty
 from pyk.prelude.k import DOTS
-from pyk.prelude.kbool import notBool
+from pyk.prelude.kbool import andBool, notBool, orBool
 from pyk.prelude.kint import INT, intToken
 from pyk.prelude.ml import mlEqualsFalse, mlEqualsTrue
 from pyk.proof.proof import Proof
@@ -1159,7 +1167,17 @@ def check_cells_equal(cell: str, nodes: Iterable[KCFG.Node]) -> bool:
 
     anti_unification = nodes[0].cterm
     for node in nodes[1:]:
-        anti_unification, _, _ = anti_unification.anti_unify(node.cterm, keep_values=True, kdef=foundry.kevm.definition)
+        anti_unification, csubst1, csubst2 = anti_unification.anti_unify(node.cterm, kdef=foundry.kevm.definition)
+        constraint1 = andBool(
+            [csubst1.pred(constraints=False, sort_with=foundry.kevm.definition)]
+            + list(map(ml_pred_to_bool, csubst1.constraints))
+        )
+        constraint2 = andBool(
+            [csubst2.pred(constraints=False, sort_with=foundry.kevm.definition)]
+            + list(map(ml_pred_to_bool, csubst2.constraints))
+        )
+        anti_unification.add_constraint(mlEqualsTrue(orBool([constraint1, constraint2])))
+
     new_node = apr_proof.kcfg.create_node(anti_unification)
     for node in nodes:
         succ = apr_proof.kcfg.successors(node.id)
diff --git a/src/tests/integration/test_foundry_prove.py b/src/tests/integration/test_foundry_prove.py
index 43aeb39c1..f29992f58 100644
--- a/src/tests/integration/test_foundry_prove.py
+++ b/src/tests/integration/test_foundry_prove.py
@@ -417,7 +417,7 @@ def test_foundry_merge_nodes(
     )
     check_pending(foundry, test, [6, 7])
 
-    foundry_merge_nodes(foundry, MergeNodesOptions({'test': test, 'nodes': [6, 7], 'include_disjunct': True}))
+    foundry_merge_nodes(foundry, MergeNodesOptions({'test': test, 'nodes': [6, 7]}))
 
     check_pending(foundry, test, [8])