diff --git a/tools/winapi/winapi.pm b/tools/winapi/winapi.pm
index 8fcaa416179..e5ed445d8e8 100644
--- a/tools/winapi/winapi.pm
+++ b/tools/winapi/winapi.pm
@@ -192,6 +192,10 @@ sub parse_api_file($$) {
 	    }
 	} elsif(defined($kind)) {
 	    my $type = $_;
+            if ($type =~ /^long\b/)
+            {
+                $output->write("$file:$linenum: type ($type) is not Win64 compatible\n");
+            }
 	    if(!$forbidden) {
 		if(defined($module)) {
 		    if($$allowed_modules_unlimited{$type}) {