Index: gtkdoc-mkdb.in
===================================================================
--- gtkdoc-mkdb.in	(revision 434)
+++ gtkdoc-mkdb.in	(working copy)
@@ -2854,6 +2855,12 @@
 		if ($return_desc) {
 		    push (@params, "Returns");
 		    push (@params, $return_desc);
+		    if ($return_style eq 'broken') {
+			print <<EOF;
+WARNING: Free-form return value description in $symbol.
+         Use `Returns:' to avoid ambiguities.
+EOF
+		    }
 		}
                 # Convert special SGML characters
                 $description = &ConvertSGMLChars ($symbol, $description);
