diff --git a/utils/post-processing/flowrate.pl b/utils/post-processing/flowrate.pl
index ac09d5e9af..a928d734f3 100755
--- a/utils/post-processing/flowrate.pl
+++ b/utils/post-processing/flowrate.pl
@@ -16,7 +16,7 @@ while (<>) {
     if (/^G1.*? F([0-9.]+)/) {
         $F = $1;
     }
-    if (/^G1 X([0-9.]+) Y([0-9.]+).*? E([0-9.]+)/) {
+    if (/^G1 X([0-9.-]+) Y([0-9.-]+).*? E([0-9.-]+)/) {
         my ($x, $y, $e) = ($1, $2, $3);
         my $e_length = $e - $E;
         if ($e_length > 0 && defined $X && defined $Y) {