diff --git a/src/SignatureXAdES_B.cpp b/src/SignatureXAdES_B.cpp
index 24d396b60..02f473b7d 100644
--- a/src/SignatureXAdES_B.cpp
+++ b/src/SignatureXAdES_B.cpp
@@ -28,6 +28,7 @@
 #include "crypto/X509CertStore.h"
 #include "crypto/X509Crypto.h"
 #include "util/DateTime.h"
+#include "util/algorithm.h"
 #include "util/log.h"
 #include "util/File.h"
 
@@ -364,7 +365,7 @@ string SignatureXAdES_B::policy() const
 {
     if(auto id = signedSignatureProperties()/"SignaturePolicyIdentifier"/"SignaturePolicyId"/"SigPolicyId"/"Identifier";
         id && id["Qualifier"] == "OIDAsURN")
-        return string(id);
+        return string(trim_prefix(id));
     return {};
 }
 
@@ -393,8 +394,8 @@ string SignatureXAdES_B::trustedSigningTime() const
 
 string SignatureXAdES_B::SPUri() const
 {
-    return string(signedSignatureProperties()
-        /"SignaturePolicyIdentifier"/"SignaturePolicyId"/"SigPolicyQualifiers"/"SigPolicyQualifier"/"SPURI");
+    return string(trim_prefix(signedSignatureProperties()
+        /"SignaturePolicyIdentifier"/"SignaturePolicyId"/"SigPolicyQualifiers"/"SigPolicyQualifier"/"SPURI"));
 }
 
 void SignatureXAdES_B::validate() const
@@ -633,7 +634,7 @@ void SignatureXAdES_B::checkSigningCertificate(bool noqscd) const
     {
         X509Cert signingCert = signingCertificate();
         vector<X509Cert::KeyUsage> usage = signingCert.keyUsage();
-        if(find(usage.cbegin(), usage.cend(), X509Cert::NonRepudiation) == usage.cend())
+        if(!contains(usage, X509Cert::NonRepudiation))
             THROW("Signing certificate does not contain NonRepudiation key usage flag");
         if(!X509CertStore::instance()->verify(signingCert, noqscd))
             THROW("Unable to verify signing certificate");
diff --git a/src/XMLDocument.h b/src/XMLDocument.h
index 5ea27733f..3783767b9 100644
--- a/src/XMLDocument.h
+++ b/src/XMLDocument.h
@@ -173,11 +173,8 @@ struct XMLElem
 
     constexpr operator sv() const noexcept
     {
-        constexpr sv whitespace {" \n\r\f\t\v"};
         auto *text = children(&value_type::children, XML_TEXT_NODE);
-        auto result = to_string_view(text, &std::decay_t<decltype(*text)>::content);
-        result.remove_prefix(std::min<size_t>(result.find_first_not_of(whitespace), result.size()));
-        return result;
+        return to_string_view(text, &std::decay_t<decltype(*text)>::content);
     }
 
     pointer d{};
diff --git a/src/util/algorithm.h b/src/util/algorithm.h
index 30911a357..683cd4953 100644
--- a/src/util/algorithm.h
+++ b/src/util/algorithm.h
@@ -54,8 +54,15 @@ constexpr bool none_of(const C &list, P pred)
 
 template<typename T>
 [[nodiscard]]
-constexpr bool starts_with(T str, T needle) {
+constexpr bool starts_with(T str, std::string_view needle) {
     return str.size() >= needle.size() && str.compare(0, needle.size(), needle) == 0;
 }
 
+[[nodiscard]]
+constexpr auto trim_prefix(std::string_view src)
+{
+    constexpr std::string_view whitespace {" \n\r\f\t\v"};
+    return src.substr(std::min<size_t>(src.find_first_not_of(whitespace), src.size()));
+}
+
 }