diff --git a/site-generator b/site-generator
index ad43184..7e1f1f0 100755
--- a/site-generator
+++ b/site-generator
@@ -238,7 +238,10 @@ sub get_filename {
 		}
 		else {
 			$filename = $$config{'filename'};
-			my $padded_index = sprintf("%04d", $$config{'id'});
+			my $padded_index = "";
+			if ($$config{'id'}) {
+				$padded_index = sprintf("%04d", $$config{'id'});
+			}
 			$filename =~ s/\[id\]/$padded_index/;
 		    return $filename;
 		}