diff --git a/src/calibre/gui2/tweak_book/boss.py b/src/calibre/gui2/tweak_book/boss.py
index a900a9a209..134c7973de 100644
--- a/src/calibre/gui2/tweak_book/boss.py
+++ b/src/calibre/gui2/tweak_book/boss.py
@@ -221,6 +221,7 @@ class Boss(QObject):
             c = current_container()
             editor.load_text(c.decode(c.open(name).read()))
         self.gui.central.show_editor(editor)
+        self.gui.keyboard.set_mode(syntax)
 
     def edit_file_requested(self, name, syntax, mime):
         if name in self.editors:
diff --git a/src/calibre/gui2/tweak_book/keyboard.py b/src/calibre/gui2/tweak_book/keyboard.py
index 6f3a7ca2cb..8c409bac48 100644
--- a/src/calibre/gui2/tweak_book/keyboard.py
+++ b/src/calibre/gui2/tweak_book/keyboard.py
@@ -31,10 +31,15 @@ class KeyboardManager(object):
             km.finalize()
 
     def set_mode(self, name):
-        km = self.modes[name]
-        for un, action in self.actions.iteritems():
-            keys = km.keys_map[un]
-            action.setShortcuts(list(keys))
-        self.current_mode = name
+        try:
+            km = self.modes[name]
+        except KeyError:
+            name = 'other'
+            km = self.modes[name]
+        if name != self.current_mode:
+            for un, action in self.actions.iteritems():
+                keys = km.keys_map[un]
+                action.setShortcuts(list(keys))
+            self.current_mode = name