--- a/browser/components/preferences/in-content/search.js
+++ b/browser/components/preferences/in-content/search.js
@@ -1,14 +1,17 @@
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 Components.utils.import("resource://gre/modules/XPCOMUtils.jsm");
-Components.utils.import("resource://gre/modules/PlacesUtils.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "PlacesUtils",
+                                  "resource://gre/modules/PlacesUtils.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "Task",
+                                  "resource://gre/modules/Task.jsm");
 
 const ENGINE_FLAVOR = "text/x-moz-search-engine";
 
 var gEngineView = null;
 
 var gSearchPane = {
 
   init: function ()
@@ -186,29 +189,23 @@ var gSearchPane = {
     let index = gEngineView.selectedIndex;
     gEngineView.rowCountChanged(index, -1);
     gEngineView.invalidate();
     gEngineView.selection.select(Math.min(index, gEngineView.lastIndex));
     gEngineView.ensureRowIsVisible(gEngineView.currentIndex);
     document.getElementById("engineList").focus();
   },
 
-  editKeyword: function(aEngine, aNewKeyword) {
+  editKeyword: Task.async(function* (aEngine, aNewKeyword) {
     if (aNewKeyword) {
-      let bduplicate = false;
       let eduplicate = false;
       let dupName = "";
 
-      try {
-        let bmserv =
-          Components.classes["@mozilla.org/browser/nav-bookmarks-service;1"]
-                    .getService(Components.interfaces.nsINavBookmarksService);
-        if (bmserv.getURIForKeyword(aNewKeyword))
-          bduplicate = true;
-      } catch(ex) {}
+      // Check for duplicates in Places keywords.
+      let bduplicate = !!(yield PlacesUtils.keywords.fetch(aNewKeyword));
 
       // Check for duplicates in changes we haven't committed yet
       let engines = gEngineView._engineStore.engines;
       for each (let engine in engines) {
         if (engine.alias == aNewKeyword &&
             engine.name != aEngine.name) {
           eduplicate = true;
           dupName = engine.name;
@@ -226,17 +223,17 @@ var gSearchPane = {
         Services.prompt.alert(window, dtitle, eduplicate ? emsg : bmsg);
         return false;
       }
     }
 
     gEngineView._engineStore.changeEngine(aEngine, "alias", aNewKeyword);
     gEngineView.invalidate();
     return true;
-  },
+  }),
 
   saveOneClickEnginesList: function () {
     let hiddenList = [];
     for (let engine of gEngineView._engineStore.engines) {
       if (!engine.shown)
         hiddenList.push(engine.name);
     }
     document.getElementById("browser.search.hiddenOneOffs").value =
@@ -514,19 +511,19 @@ EngineView.prototype = {
     if (column.id == "engineShown") {
       this._engineStore.engines[index].shown = value == "true";
       gEngineView.invalidate();
       gSearchPane.saveOneClickEnginesList();
     }
   },
   setCellText: function(index, column, value) {
     if (column.id == "engineKeyword") {
-      if (!gSearchPane.editKeyword(this._engineStore.engines[index], value)) {
-        setTimeout(() => {
+      gSearchPane.editKeyword(this._engineStore.engines[index], value)
+                 .then(valid => {
+        if (!valid)
           document.getElementById("engineList").startEditing(index, column);
-        }, 0);
-      }
+      });
     }
   },
   performAction: function(action) { },
   performActionOnRow: function(action, index) { },
   performActionOnCell: function(action, index, column) { }
 };

--- a/browser/components/preferences/search.js
+++ b/browser/components/preferences/search.js
@@ -1,14 +1,17 @@
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 Components.utils.import("resource://gre/modules/XPCOMUtils.jsm");
-Components.utils.import("resource://gre/modules/PlacesUtils.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "PlacesUtils",
+                                  "resource://gre/modules/PlacesUtils.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "Task",
+                                  "resource://gre/modules/Task.jsm");
 
 const ENGINE_FLAVOR = "text/x-moz-search-engine";
 
 var gEngineView = null;
 
 var gSearchPane = {
 
   init: function ()
@@ -118,29 +121,23 @@ var gSearchPane = {
     let index = gEngineView.selectedIndex;
     gEngineView.rowCountChanged(index, -1);
     gEngineView.invalidate();
     gEngineView.selection.select(Math.min(index, gEngineView.lastIndex));
     gEngineView.ensureRowIsVisible(gEngineView.currentIndex);
     document.getElementById("engineList").focus();
   },
 
-  editKeyword: function(aEngine, aNewKeyword) {
+  editKeyword: Task.async(function* (aEngine, aNewKeyword) {
     if (aNewKeyword) {
-      let bduplicate = false;
       let eduplicate = false;
       let dupName = "";
 
-      try {
-        let bmserv =
-          Components.classes["@mozilla.org/browser/nav-bookmarks-service;1"]
-                    .getService(Components.interfaces.nsINavBookmarksService);
-        if (bmserv.getURIForKeyword(aNewKeyword))
-          bduplicate = true;
-      } catch(ex) {}
+      // Check for duplicates in Places keywords.
+      let bduplicate = !!(yield PlacesUtils.keywords.fetch(aNewKeyword));
 
       // Check for duplicates in changes we haven't committed yet
       let engines = gEngineView._engineStore.engines;
       for each (let engine in engines) {
         if (engine.alias == aNewKeyword &&
             engine.name != aEngine.name) {
           eduplicate = true;
           dupName = engine.name;
@@ -158,17 +155,17 @@ var gSearchPane = {
         Services.prompt.alert(window, dtitle, eduplicate ? emsg : bmsg);
         return false;
       }
     }
 
     gEngineView._engineStore.changeEngine(aEngine, "alias", aNewKeyword);
     gEngineView.invalidate();
     return true;
-  },
+  }),
 
   saveOneClickEnginesList: function () {
     let hiddenList = [];
     for (let engine of gEngineView._engineStore.engines) {
       if (!engine.shown)
         hiddenList.push(engine.name);
     }
     document.getElementById("browser.search.hiddenOneOffs").value =
@@ -529,19 +526,19 @@ EngineView.prototype = {
     if (column.id == "engineShown") {
       this._engineStore.engines[index].shown = value == "true";
       gEngineView.invalidate();
       gSearchPane.saveOneClickEnginesList();
     }
   },
   setCellText: function(index, column, value) {
     if (column.id == "engineKeyword") {
-      if (!gSearchPane.editKeyword(this._engineStore.engines[index], value)) {
-        setTimeout(() => {
+      gSearchPane.editKeyword(this._engineStore.engines[index], value)
+                 .then(valid => {
+        if (!valid)
           document.getElementById("engineList").startEditing(index, column);
-        }, 0);
-      }
+      });
     }
   },
   performAction: function(action) { },
   performActionOnRow: function(action, index) { },
   performActionOnCell: function(action, index, column) { }
 };

--- a/browser/components/search/content/engineManager.js
+++ b/browser/components/search/content/engineManager.js
@@ -1,13 +1,18 @@
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
+Components.utils.import("resource://gre/modules/XPCOMUtils.jsm");
 Components.utils.import("resource://gre/modules/Services.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "PlacesUtils",
+                                  "resource://gre/modules/PlacesUtils.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "Task",
+                                  "resource://gre/modules/Task.jsm");
 
 const Ci = Components.interfaces;
 const Cc = Components.classes;
 
 const ENGINE_FLAVOR = "text/x-moz-search-engine";
 
 const BROWSER_SUGGEST_PREF = "browser.search.suggest.enabled";
 
@@ -100,38 +105,34 @@ var gEngineManagerDialog = {
 
     gEngineView.invalidate();
     gEngineView.selection.select(newIndex);
     gEngineView.ensureRowIsVisible(newIndex);
     this.showRestoreDefaults(true);
     document.getElementById("engineList").focus();
   },
 
-  editKeyword: function engineManager_editKeyword() {
+  editKeyword: Task.async(function* () {
     var selectedEngine = gEngineView.selectedEngine;
     if (!selectedEngine)
       return;
 
     var alias = { value: selectedEngine.alias };
     var strings = document.getElementById("engineManagerBundle");
     var title = strings.getString("editTitle");
     var msg = strings.getFormattedString("editMsg", [selectedEngine.name]);
 
     while (Services.prompt.prompt(window, title, msg, alias, null, {})) {
       var bduplicate = false;
       var eduplicate = false;
       var dupName = "";
 
       if (alias.value != "") {
-        try {
-          let bmserv = Cc["@mozilla.org/browser/nav-bookmarks-service;1"].
-                       getService(Ci.nsINavBookmarksService);
-          if (bmserv.getURIForKeyword(alias.value))
-            bduplicate = true;
-        } catch(ex) {}
+        // Check for duplicates in Places keywords.
+        bduplicate = !!(yield PlacesUtils.keywords.fetch(alias.value));
 
         // Check for duplicates in changes we haven't committed yet
         let engines = gEngineView._engineStore.engines;
         for each (let engine in engines) {
           if (engine.alias == alias.value &&
               engine.name != selectedEngine.name) {
             eduplicate = true;
             dupName = engine.name;
@@ -149,17 +150,17 @@ var gEngineManagerDialog = {
         Services.prompt.alert(window, dtitle, eduplicate ? emsg : bmsg);
       } else {
         gEngineView._engineStore.changeEngine(selectedEngine, "alias",
                                               alias.value);
         gEngineView.invalidate();
         break;
       }
     }
-  },
+  }),
 
   onSelect: function engineManager_onSelect() {
     // Buttons only work if an engine is selected and it's not the last engine,
     // the latter is true when the selected is first and last at the same time.
     var lastSelected = (gEngineView.selectedIndex == gEngineView.lastIndex);
     var firstSelected = (gEngineView.selectedIndex == 0);
     var noSelection = (gEngineView.selectedIndex == -1);
 

--- a/browser/components/search/content/engineManager.xul
+++ b/browser/components/search/content/engineManager.xul
@@ -31,17 +31,17 @@
              disabled="true"/>
     <command id="cmd_moveup"
              oncommand="gEngineManagerDialog.bump(1);"
              disabled="true"/>
     <command id="cmd_movedown"
              oncommand="gEngineManagerDialog.bump(-1);"
              disabled="true"/>
     <command id="cmd_editkeyword"
-             oncommand="gEngineManagerDialog.editKeyword();"
+             oncommand="gEngineManagerDialog.editKeyword().catch(Components.utils.reportError);"
              disabled="true"/>
   </commandset>
 
   <keyset id="engineManagerKeyset">
     <key id="delete" keycode="VK_DELETE" command="cmd_remove"/>
   </keyset>
 
   <stringbundleset id="engineManagerBundleset">