diff --git a/docs/tutorials/python/predict_image.md b/docs/tutorials/python/predict_image.md
index a9a0d29010c1..8be98d991366 100644
--- a/docs/tutorials/python/predict_image.md
+++ b/docs/tutorials/python/predict_image.md
@@ -69,6 +69,7 @@ def get_image(url, show=False):
     img = mx.image.imresize(img, 224, 224) # resize
     img = img.transpose((2, 0, 1)) # Channel first
     img = img.expand_dims(axis=0) # batchify
+    img = img.astype('float32') # for gpu context
     return img
 
 def predict(url):