diff --git a/keras/applications/nasnet.py b/keras/applications/nasnet.py
index 6ee93e613a3..5f171c79ccf 100644
--- a/keras/applications/nasnet.py
+++ b/keras/applications/nasnet.py
@@ -384,6 +384,8 @@ def NASNetMobile(
             "at this time due to an outstanding bug. "
             "If interested, please open a PR."
         )
+    if (include_top == False) and (input_shape == None):
+        input_shape = (224, 224, 3)
     return NASNet(
         input_shape,
         penultimate_filters=1056,