diff --git a/virtualenv.py b/virtualenv.py
index c008a395d..e7e7111e4 100755
--- a/virtualenv.py
+++ b/virtualenv.py
@@ -895,6 +895,7 @@ def space_path2url(p):
         "PIP_USE_WHEEL": "1",
         "PIP_ONLY_BINARY": ":all:",
         "PIP_USER": "0",
+        "PIP_NO_INPUT": "1"
     }
 
     if not download: