diff --git a/src/saveload/saveload.cpp b/src/saveload/saveload.cpp
index 2b5f4a411a..aa5041a933 100644
--- a/src/saveload/saveload.cpp
+++ b/src/saveload/saveload.cpp
@@ -1782,6 +1782,7 @@ size_t SlCalcObjMemberLength(const void *object, const SaveLoad *sld)
 		case SL_ARR:
 		case SL_STR:
 		case SL_LST:
+		case SL_PTRDEQ:
 		case SL_VEC:
 		case SL_DEQUE:
 		case SL_STDSTR: