diff --git a/gears.scad b/gears.scad
index 3433a617..65696099 100644
--- a/gears.scad
+++ b/gears.scad
@@ -1054,6 +1054,7 @@ module spur_gear(
                         clearance = clearance,
                         backlash = backlash,
                         internal = internal,
+                        shorten = shorten,
                         profile_shift = profile_shift,
                         shaft_diam = shaft_diam
                     );