diff --git a/Shorewall/Perl/Shorewall/Tc.pm b/Shorewall/Perl/Shorewall/Tc.pm
index c5418e947..4303c16bc 100644
--- a/Shorewall/Perl/Shorewall/Tc.pm
+++ b/Shorewall/Perl/Shorewall/Tc.pm
@@ -1002,7 +1002,7 @@ sub convert_delay( $ ) {
     my $delay = shift;
 
     return 0 unless $delay;
-    return $1 if $delay =~ /^(\d+)(ms)?$/;
+    return $1 if $delay =~ /^(\d+(\.\d+)?)(ms)?$/;
     fatal_error "Invalid Delay ($delay)";
 }