--- a/devtools/client/framework/test/browser_keybindings_02.js
+++ b/devtools/client/framework/test/browser_keybindings_02.js
@@ -49,17 +49,16 @@ function zoomWithKey(toolbox, key) {
   let currentZoom = getZoomValue();
   synthesizeKeyShortcut(shortcut, toolbox.win);
   isnot(getZoomValue(), currentZoom, "The zoom level was changed in the toolbox");
 }
 
 function checkKeyBindings(toolbox) {
   zoomWithKey(toolbox, "toolbox.zoomIn.key");
   zoomWithKey(toolbox, "toolbox.zoomIn2.key");
-  zoomWithKey(toolbox, "toolbox.zoomIn3.key");
 
   zoomWithKey(toolbox, "toolbox.zoomReset.key");
 
   zoomWithKey(toolbox, "toolbox.zoomOut.key");
   zoomWithKey(toolbox, "toolbox.zoomOut2.key");
 
   zoomWithKey(toolbox, "toolbox.zoomReset2.key");
 }

--- a/devtools/client/locales/en-US/toolbox.properties
+++ b/devtools/client/locales/en-US/toolbox.properties
@@ -106,17 +106,16 @@ toolbox.nextTool.key=CmdOrCtrl+]
 # Key shortcut used to select the previous tool
 toolbox.previousTool.key=CmdOrCtrl+[
 
 # LOCALIZATION NOTE (toolbox.zoom*.key)
 # Key shortcuts used to zomm in/out or reset the toolbox
 # Should match fullZoom*Cmd.commandkey values from browser.dtd
 toolbox.zoomIn.key=CmdOrCtrl+Plus
 toolbox.zoomIn2.key=CmdOrCtrl+=
-toolbox.zoomIn3.key=
 
 toolbox.zoomOut.key=CmdOrCtrl+-
 toolbox.zoomOut2.key=
 
 toolbox.zoomReset.key=CmdOrCtrl+0
 toolbox.zoomReset2.key=
 
 # LOCALIZATION NOTE (toolbox.reload*.key)

--- a/devtools/client/shared/zoom-keys.js
+++ b/devtools/client/shared/zoom-keys.js
@@ -61,20 +61,16 @@ exports.register = function(window) {
   // Set zoom to whatever the last setting was.
   setZoom(zoomValue);
 
   shortcuts.on(L10N.getStr("toolbox.zoomIn.key"), zoomIn);
   let zoomIn2 = L10N.getStr("toolbox.zoomIn2.key");
   if (zoomIn2) {
     shortcuts.on(zoomIn2, zoomIn);
   }
-  let zoomIn3 = L10N.getStr("toolbox.zoomIn3.key");
-  if (zoomIn3) {
-    shortcuts.on(zoomIn3, zoomIn);
-  }
 
   shortcuts.on(L10N.getStr("toolbox.zoomOut.key"),
                zoomOut);
   let zoomOut2 = L10N.getStr("toolbox.zoomOut2.key");
   if (zoomOut2) {
     shortcuts.on(zoomOut2, zoomOut);
   }