diff --git a/code/Common/Subdivision.cpp b/code/Common/Subdivision.cpp
index fc8ab20991..78c249807d 100644
--- a/code/Common/Subdivision.cpp
+++ b/code/Common/Subdivision.cpp
@@ -524,7 +524,11 @@ void CatmullClarkSubdivider::InternSubdivide(
                                     }
                                 }
 
-                                ai_assert(adj[o] - moffsets[nidx].first < mp->mNumFaces);
+                                if (mp == nullptr) {
+                                    continue;
+                                }
+
+                                ai_assert(adj[o] - moffsets[nidx].first < mp->mNumFaces);                                
                                 const aiFace &f = mp->mFaces[adj[o] - moffsets[nidx].first];
                                 bool haveit = false;