diff --git a/shmup.cpp b/shmup.cpp
index 71c5aa5c..fdc0fafa 100644
--- a/shmup.cpp
+++ b/shmup.cpp
@@ -1655,7 +1655,7 @@ void movePlayer(monster *m, int delta) {
   
   godir[cpid] = 0;
 
-  if(WDIM == 2 && GDIM == 3) {
+  if(WDIM == 2 && GDIM == 3 && (mdx || mdy)) {
     double mdd = hypot(mdx, mdy);
     godir[cpid] = -atan2(mdx, -mdy);
     mgo += mdd;