diff --git a/Shorewall/Perl/Shorewall/Chains.pm b/Shorewall/Perl/Shorewall/Chains.pm
index fa69edfb8..e003a85e1 100644
--- a/Shorewall/Perl/Shorewall/Chains.pm
+++ b/Shorewall/Perl/Shorewall/Chains.pm
@@ -4698,7 +4698,7 @@ sub load_isocodes() {
 
     my @codes = `ls $isodir/*$family 2>/dev/null`;
 
-    fatal_error "$isodir does not exist or is empty" unless @codes;
+    fatal_error "$isodir contains no IPv${family} entries" unless @codes;
 
     $isocodes{substr(basename($_),0,2)} = 1 for @codes;
 }