--- a/devtools/client/debugger/content/views/sources-view.js
+++ b/devtools/client/debugger/content/views/sources-view.js
@@ -1175,19 +1175,20 @@ SourcesView.prototype = Heritage.extend(
     }
   },
 
   /**
    * Called when the add conditional breakpoint key sequence was pressed.
    */
   _onCmdAddConditionalBreakpoint: function(e) {
     let actor = this.selectedValue;
-    let line = (e && e.sourceEvent.target.tagName == 'menuitem' ?
+    let line = (this.DebuggerView.clickedLine ?
                 this.DebuggerView.clickedLine + 1 :
                 this.DebuggerView.editor.getCursor().line + 1);
+
     let location = { actor, line };
     let bp = getBreakpoint(this.getState(), location);
 
     // If a breakpoint already existed or wasn't a conditional, morph it now.
     if (bp) {
       this.highlightBreakpoint(bp.location, { openPopup: true });
     }
     // No breakpoint existed at the required location, add one now.