diff --git a/tests/syntax-tests/create_highlighted_versions.py b/tests/syntax-tests/create_highlighted_versions.py
index 20357d24..a9f21ced 100755
--- a/tests/syntax-tests/create_highlighted_versions.py
+++ b/tests/syntax-tests/create_highlighted_versions.py
@@ -91,7 +91,7 @@ def create_highlighted_versions(output_basepath):
             p.map(create_highlighted_version, sources)
     except subprocess.CalledProcessError as err:
         print(
-            "=== Error: Could not highlight source file '{}".format(source),
+            "=== Error: Could not highlight source file:\n" + " ".join(err.cmd),
             file=sys.stderr,
         )
         print(