diff --git a/po4a.spec b/po4a.spec
index 564265b..92bc183 100644
--- a/po4a.spec
+++ b/po4a.spec
@@ -28,6 +28,7 @@ Group:          Development/Tools/Other
 %endif
 URL:            https://po4a.org/
 Source:         https://github.com/mquinson/po4a/releases/download/v%{version}/%{name}-%{version}.tar.gz
+# PATCH-FIX-UPSTREAM Workaround for build error with perl 5.40, see https://github.com/mquinson/po4a/issues/508
 Patch0:         po4a.diff
 
 %if "%{_vendor}" == "debbuild"