diff --git a/testing/run_fates_tests.py b/testing/run_fates_tests.py
index 6816e034ad..ea2cf5b0b1 100755
--- a/testing/run_fates_tests.py
+++ b/testing/run_fates_tests.py
@@ -432,7 +432,7 @@ def check_arg_validity(args):
     # make sure build directory exists
     if args.skip_build:
         if args.verbose_make:
-            raise argparse.ArgumentError(None, f"Can't run verbose make and skip build.\n" 
+            raise argparse.ArgumentError(None, "Can't run verbose make and skip build.\n" 
                                          "Re-run script without --skip-build")
         check_build_dir(args.build_dir, args.test_dict)