diff --git a/.gitlab-ci/sanitize-docker.pl b/.gitlab-ci/sanitize-docker.pl
index 51704aebe..1cb3dd4dc 100755
--- a/.gitlab-ci/sanitize-docker.pl
+++ b/.gitlab-ci/sanitize-docker.pl
@@ -154,7 +154,7 @@ my ($outerjson, $imageid) = ();
   opendir($dirh, '.') or die "Could not read dir '.', because: $!";
   while(my $fn = readdir($dirh)) {
     next if $fn=~m#^\.#;
-    if($fn=~m#(.*)\.json#) {
+    if($fn=~m#(.{16,})\.json#) { # it shall match on hash sums but not for example on manifest.json
       $outerjson = $1;
       next
     }