diff --git a/pip/wheel.py b/pip/wheel.py
index 2d4f4df7570..739eaf9280a 100644
--- a/pip/wheel.py
+++ b/pip/wheel.py
@@ -242,6 +242,10 @@ def is_entrypoint_wrapper(name):
 
     maker = ScriptMaker(None, scheme['scripts'])
 
+    # Ensure old scripts are overwritten.
+    # See https://github.com/pypa/pip/issues/1800
+    maker.clobber = True
+
     # Ensure we don't generate any variants for scripts because this is almost
     # never what somebody wants.
     # See https://bitbucket.org/pypa/distlib/issue/35/