diff --git a/browser/devtools/shared/inplace-editor.js b/browser/devtools/shared/inplace-editor.js
index 45a6871e4e2..3058304b038 100644
--- a/browser/devtools/shared/inplace-editor.js
+++ b/browser/devtools/shared/inplace-editor.js
@@ -720,7 +720,8 @@ InplaceEditor.prototype = {
   _cycleCSSSuggestion:
   function InplaceEditor_cycleCSSSuggestion(aReverse, aNoSelect)
   {
-    let {label, preLabel} = this.popup.selectedItem;
+    // selectedItem can be null when nothing is selected in an empty editor.
+    let {label, preLabel} = this.popup.selectedItem || {label: "", preLabel: ""};
     if (aReverse) {
       this.popup.selectPreviousItem();
     } else {
@@ -872,7 +873,7 @@ InplaceEditor.prototype = {
       if (this.popup && this.popup.isOpen) {
         this.popup.hidePopup();
       }
-    } else if (!cycling) {
+    } else if (!cycling && !aEvent.metaKey && !aEvent.altKey && !aEvent.ctrlKey) {
       this._maybeSuggestCompletion();
     }
 
diff --git a/browser/devtools/styleinspector/test/browser_bug894376_css_value_completion_new_property_value_pair.js b/browser/devtools/styleinspector/test/browser_bug894376_css_value_completion_new_property_value_pair.js
index fba13b8e284..f052936c707 100644
--- a/browser/devtools/styleinspector/test/browser_bug894376_css_value_completion_new_property_value_pair.js
+++ b/browser/devtools/styleinspector/test/browser_bug894376_css_value_completion_new_property_value_pair.js
@@ -21,9 +21,11 @@ let brace;
 //    total items in the popup
 //  ]
 let testData = [
+  ["a", {accelKey: true, ctrlKey: true}, "", -1, 0],
   ["d", {}, "direction", 0, 3],
   ["VK_DOWN", {}, "display", 1, 3],
   ["VK_TAB", {}, "", -1, 10],
+  ["VK_DOWN", {}, "-moz-box", 0, 10],
   ["n", {}, "none", -1, 0],
   ["VK_TAB", {shiftKey: true}, "display", -1, 0],
   ["VK_BACK_SPACE", {}, "", -1, 0],
@@ -85,7 +87,8 @@ function checkStateAndMoveOn(index) {
       checkState();
     });
   }
-  else if (/(right|back_space|escape|return)/ig.test(key)) {
+  else if (/(right|back_space|escape|return)/ig.test(key) ||
+           (modifiers.accelKey || modifiers.ctrlKey)) {
     info("added event listener for right|escape|back_space|return keys");
     editor.input.addEventListener("keypress", function onKeypress() {
       if (editor.input) {