diff --git a/utils/datasets.py b/utils/datasets.py
index ef726e60..340cfdb8 100755
--- a/utils/datasets.py
+++ b/utils/datasets.py
@@ -425,7 +425,7 @@ class LoadImagesAndLabels(Dataset):  # for training/testing
             # Letterbox
             h, w = img.shape[:2]
             shape = self.batch_shapes[self.batch[index]] if self.rect else self.img_size  # final letterboxed shape
-            img, ratio, pad = letterbox(img, shape, auto=False)
+            img, ratio, pad = letterbox(img, shape, auto=False, scaleup=self.augment)
 
             # Load labels
             labels = []
@@ -609,16 +609,16 @@ def load_mosaic(self, index):
     return img4, labels4
 
 
-def letterbox(img, new_shape=(416, 416), color=(128, 128, 128), auto=True, scaleFill=False, interp=cv2.INTER_AREA):
+def letterbox(img, new_shape=(416, 416), color=(128, 128, 128),
+              auto=True, scaleFill=False, scaleup=True, interp=cv2.INTER_AREA):
     # Resize image to a 32-pixel-multiple rectangle https://github.com/ultralytics/yolov3/issues/232
     shape = img.shape[:2]  # current shape [height, width]
     if isinstance(new_shape, int):
         new_shape = (new_shape, new_shape)
 
     # Scale ratio (new / old)
-    scaleup_ok = True
     r = max(new_shape) / max(shape)
-    if not scaleup_ok:  # only scale down
+    if not scaleup:  # only scale down, do not scale up (for better test mAP)
         r = min(r, 1.0)
 
     # Compute padding