diff --git a/builtins.scad b/builtins.scad
index d4f46ee..b1dd295 100644
--- a/builtins.scad
+++ b/builtins.scad
@@ -23,7 +23,7 @@ module _cube(size,center) cube(size,center=center);
 
 module _cylinder(h,r1,r2,center,r,d,d1,d2) cylinder(h,r=r,d=d,r1=r1,r2=r2,d1=d1,d2=d2,center=center);
 
-module _sphere(r,center,d) sphere(r=r,d=d,center=center);
+module _sphere(r,d) sphere(r=r,d=d);