diff --git a/nonisotropic.cpp b/nonisotropic.cpp
index 859ad836..56f10946 100644
--- a/nonisotropic.cpp
+++ b/nonisotropic.cpp
@@ -776,7 +776,7 @@ EX namespace nilv {
     { point31(0,0,0.5), point31(-0.5,0.5,0.25), point31(-0.5,-0.5,0.75), point31(0,0,0.5), point31(-0.5,-0.5,0.75), point31(-0.5,-0.5,0.5), point31(0,0,0.5), point31(-0.5,-0.5,0.5), point31(0.5,-0.5,0.5), point31(0,0,0.5), point31(0.5,-0.5,0.5), point31(0.5,-0.5,0.25), point31(0,0,0.5), point31(0.5,-0.5,0.25), point31(0.5,0.5,0.75), point31(0,0,0.5), point31(0.5,0.5,0.75), point31(0.5,0.5,0.5), point31(0,0,0.5), point31(0.5,0.5,0.5), point31(-0.5,0.5,0.5), point31(0,0,0.5), point31(-0.5,0.5,0.5), point31(-0.5,0.5,0.25), },
     }};
 
-  EX int zgmod(int a, int b) { return b ? a%b : a; }
+  EX int zgmod(int a, int b) { return b ? gmod(a, b) : a; }
 
   array<int,3> nilperiod, nilperiod_edit;