diff --git a/src/pokemon_storage_system.c b/src/pokemon_storage_system.c
index db8f3d2bb4..4be1cf729f 100644
--- a/src/pokemon_storage_system.c
+++ b/src/pokemon_storage_system.c
@@ -8408,8 +8408,13 @@ static void sub_80D08CC(void)
         for (j = sMoveMonsPtr->minRow; j < rowCount; j++)
         {
             struct BoxPokemon *boxMon = GetBoxedMonPtr(boxId, boxPosition);
-
+            // UB: possible null dereference
+#ifdef UBFIX
+            if (boxMon != NULL)
+                sMoveMonsPtr->boxMons[monArrayId] = *boxMon;
+#else
             sMoveMonsPtr->boxMons[monArrayId] = *boxMon;
+#endif
             monArrayId++;
             boxPosition++;
         }