diff --git a/rpcs3/Emu/Cell/Modules/cellSysutilAvc2.cpp b/rpcs3/Emu/Cell/Modules/cellSysutilAvc2.cpp
index e3bad96060..9456867599 100644
--- a/rpcs3/Emu/Cell/Modules/cellSysutilAvc2.cpp
+++ b/rpcs3/Emu/Cell/Modules/cellSysutilAvc2.cpp
@@ -247,7 +247,7 @@ error_code cellSysutilAvc2SetWindowString(SceNpMatching2RoomMemberId member_id,
 {
 	cellSysutilAvc2.todo("cellSysutilAvc2SetWindowString(member_id=0x%x, string=%s)", member_id, string);
 
-	if (!string) // TODO something > 0x3F (63)
+	if (!string || std::strlen(string.get_ptr()) >= 64)
 		return CELL_AVC2_ERROR_INVALID_ARGUMENT;
 
 	return CELL_OK;