diff -r d7cbaaba59e8 Lib/idlelib/query.py
--- a/Lib/idlelib/query.py	Tue Jul 26 06:47:09 2016 +0000
+++ b/Lib/idlelib/query.py	Tue Jul 26 10:20:01 2016 +0300
@@ -52,7 +52,7 @@ class Query(Toplevel):
         self.title(title)
         self.transient(parent)
         self.grab_set()
-        self.bind('<Key-Return>', self.ok)
+        self.bind('<Key-Return>', self._press_return)
         self.bind('<Key-Escape>', self.cancel)
         self.protocol("WM_DELETE_WINDOW", self.cancel)
         self.parent = parent
@@ -104,6 +104,12 @@ class Query(Toplevel):
             return None
         return entry
 
+    def _press_return(self, event):
+        if event.widget is self.button_cancel:
+            self.cancel(event)
+        else:
+            self.ok(event)
+
     def ok(self, event=None):  # Do not replace.
         '''If entry is valid, bind it to 'result' and destroy tk widget.