diff --git a/src/lib/libdll/features/dll b/src/lib/libdll/features/dll
index 93b53c243..f530a3b87 100644
--- a/src/lib/libdll/features/dll
+++ b/src/lib/libdll/features/dll
@@ -261,4 +261,6 @@ tst	- output{
 		printf("\n");
 		return 0;
 	}
+}end fail{
+	echo '#error The output block in src/lib/libdll/features/dll failed to compile'
 }end