diff --git a/controller/relay-image.go b/controller/relay-image.go
index 2f2e57cf..3ff7dc18 100644
--- a/controller/relay-image.go
+++ b/controller/relay-image.go
@@ -96,6 +96,8 @@ func relayImageHelper(c *gin.Context, relayMode int) *OpenAIErrorWithStatusCode
 				sizeRatio *= 1.5
 			}
 		}
+	} else {
+		return errorWrapper(errors.New("size not supported"), "size_not_supported", http.StatusBadRequest)
 	}
 
 	quota := int(ratio*sizeRatio*1000) * imageRequest.N