diff --git a/test/ForwardMode/MemberFunctions.C b/test/ForwardMode/MemberFunctions.C
index 96f914500..51764c42e 100644
--- a/test/ForwardMode/MemberFunctions.C
+++ b/test/ForwardMode/MemberFunctions.C
@@ -1,9 +1,7 @@
 // RUN: %cladclang %s -I%S/../../include -oMemberFunctions.out 2>&1 | %filecheck %s
 // RUN: ./MemberFunctions.out | %filecheck_exec %s
-// RUN: %cladclang -std=c++14 %s -I%S/../../include -oMemberFunctions-cpp14.out 2>&1 | %filecheck %s
-// RUN: ./MemberFunctions-cpp14.out | %filecheck_exec %s
-// RUN: %cladclang -std=c++17 %s -I%S/../../include -oMemberFunctions-cpp17.out 2>&1 | %filecheck %s
-// RUN: ./MemberFunctions-cpp17.out | %filecheck_exec %s
+// RUN: %cladclang -std=c++20 %s -I%S/../../include -oMemberFunctions-cpp20.out 2>&1 | %filecheck %s
+// RUN: ./MemberFunctions-cpp20.out | %filecheck_exec %s
 
 #include "clad/Differentiator/Differentiator.h"
 
diff --git a/test/lit.cfg b/test/lit.cfg
index afe312970..e3e8317c4 100644
--- a/test/lit.cfg
+++ b/test/lit.cfg
@@ -253,7 +253,7 @@ if not lit_config.quiet:
 lit.util.usePlatformSdkOnDarwin(config, lit_config)
 
 #Start clad forwarding to:
-#clang -std=c++11 some-input-file.c -Xclang -add-plugin -Xclang ad -Xclang
+#clang -std=c++20 some-input-file.c -Xclang -add-plugin -Xclang ad -Xclang
 #\ -plugin-arg-ad -Xclang -fdump-derived-fn -Xclang -load -Xclang../../Debug+Asserts/lib/libclad.so
 #FIXME: we need to introduce a better way to check compatible version of clang, propagating
 #-fvalidate-clang-version flag is not enough.
@@ -261,9 +261,9 @@ flags = ' -Xclang -add-plugin -Xclang clad -Xclang \
         -plugin-arg-clad -Xclang -fdump-derived-fn -Xclang \
         -load -Xclang ' + config.cladlib
 
-config.substitutions.append( ('%cladclang_cuda', config.clang + ' -std=c++17' + flags) )
+config.substitutions.append( ('%cladclang_cuda', config.clang + ' -std=c++20' + flags) )
 
-config.substitutions.append( ('%cladclang', config.clang + '++ -DCLAD_NO_NUM_DIFF ' + ' -std=c++14' + flags) )
+config.substitutions.append( ('%cladclang', config.clang + '++ -DCLAD_NO_NUM_DIFF ' + ' -std=c++20' + flags) )
 
 config.substitutions.append( ('%cladlib', config.cladlib) )