diff --git a/rpcs3/Emu/RSX/RSXThread.h b/rpcs3/Emu/RSX/RSXThread.h
index fa6b772143..9e999fcfe8 100644
--- a/rpcs3/Emu/RSX/RSXThread.h
+++ b/rpcs3/Emu/RSX/RSXThread.h
@@ -208,7 +208,7 @@ namespace rsx
 			}
 
 			const u32 max_index = (first + count) - 1;
-			u32 _max_index = first;
+			u32 _max_index = 0;
 			u32 _min_index = first;
 
 			for (const auto &attrib : locations)
@@ -242,6 +242,7 @@ namespace rsx
 				}
 			}
 
+			verify(HERE), _max_index >= _min_index;
 			return { _min_index, (_max_index - _min_index) + 1 };
 		}
 	};