diff --git a/git2spec.pl b/git2spec.pl
index 7853791e..9ddc3805 100755
--- a/git2spec.pl
+++ b/git2spec.pl
@@ -37,7 +37,7 @@ $tag=`git describe --abbrev=0 --tags` if not defined $tag;
 chomp($tag);
 my @patches=&create_patches($tag, $pdir);
 my $num=$#patches + 2;
-$tag=~s/[^0-9]+?([0-9]+)/$1/;
+$tag=~s/[^0-9]+?([0-9]+)/$1/ if $tag !~ /\b[0-9a-f]{5,40}\b/;
 my $release="$num.git$datestr";
 $release="1" if $num == 1;