diff --git a/panda/src/bullet/bullet_utils.cxx b/panda/src/bullet/bullet_utils.cxx
index 2cffee834b..c9dcb018f1 100644
--- a/panda/src/bullet/bullet_utils.cxx
+++ b/panda/src/bullet/bullet_utils.cxx
@@ -137,7 +137,7 @@ CPT(TransformState) btTrans_to_TransformState(const btTransform &trans, const LV
 //     Function: TransformState_to_btTrans
 //  Description: 
 ////////////////////////////////////////////////////////////////////
-btTransform TransformState_to_btTrans(CPT(TransformState) &ts) {
+btTransform TransformState_to_btTrans(CPT(TransformState) ts) {
 
   ts = ts->set_scale(1.0);
 
diff --git a/panda/src/bullet/bullet_utils.h b/panda/src/bullet/bullet_utils.h
index 6e9d1e5a93..6c6302c04b 100644
--- a/panda/src/bullet/bullet_utils.h
+++ b/panda/src/bullet/bullet_utils.h
@@ -46,7 +46,7 @@ EXPCL_PANDABULLET CPT(TransformState) btTrans_to_TransformState(
   const LVecBase3f &scale=LVecBase3f(1.0f, 1.0f, 1.0f));
 
 EXPCL_PANDABULLET btTransform TransformState_to_btTrans(
-  CPT(TransformState) &ts);
+  CPT(TransformState) ts);
 
 // UpAxis
 BEGIN_PUBLISH