diff --git a/common/content/mappings.js b/common/content/mappings.js
index eb4e032d..bdad8699 100644
--- a/common/content/mappings.js
+++ b/common/content/mappings.js
@@ -355,6 +355,15 @@ function Mappings() //{{{
          */
         getUserIterator: function (mode) mappingsIterator(mode, user),
 
+        addMode: function (mode)
+        {
+            if (!(mode in user || mode in main))
+            {
+                main[mode] = [];
+                user[mode] = [];
+            }
+        },
+
         /**
          * Adds a new default key mapping.
          *
diff --git a/common/content/modes.js b/common/content/modes.js
index 2c9932ce..4c742831 100644
--- a/common/content/modes.js
+++ b/common/content/modes.js
@@ -134,6 +134,8 @@ const modes = (function () //{{{
             modeMap[name].display = modeMap[name].display || function () disp;
             if (!extended)
                 mainModes.push(this[name]);
+            if ("mappings" in modules)
+                mappings.addMode(this[name]);
         },
 
         getMode: function (name) modeMap[name],