diff --git a/panda/src/mathutil/boundingSphere.cxx b/panda/src/mathutil/boundingSphere.cxx
index 32e48adad9..beb6cb6309 100644
--- a/panda/src/mathutil/boundingSphere.cxx
+++ b/panda/src/mathutil/boundingSphere.cxx
@@ -112,6 +112,10 @@ xform(const LMatrix4 &mat) {
 
     // Transform the center
     _center = _center * mat;
+
+    if (cinf(_radius)) {
+      set_infinite();
+    }
   }
 }