diff --git a/lib/checksrc.pl b/lib/checksrc.pl
index f9d076a2f..78b9cef5b 100755
--- a/lib/checksrc.pl
+++ b/lib/checksrc.pl
@@ -442,7 +442,7 @@ sub scanfile {
 
         # crude attempt to detect // comments without too many false
         # positives
-        if($l =~ /^([^"\*]*)[^:"]\/\//) {
+        if($l =~ /^(([^"\*]*)[^:"]|)\/\//) {
             checkwarn("CPPCOMMENTS",
                       $line, length($1), $file, $l, "\/\/ comment");
         }