diff --git a/content/events/src/nsDOMEvent.cpp b/content/events/src/nsDOMEvent.cpp
index 1681c264da5d..4652bd3aee65 100644
--- a/content/events/src/nsDOMEvent.cpp
+++ b/content/events/src/nsDOMEvent.cpp
@@ -704,15 +704,6 @@ nsDOMEvent::DuplicatePrivateData()
       newEvent = newFocusEvent;
       break;
     }
-
-    case NS_POPUP_EVENT:
-    {
-      newEvent = new nsInputEvent(false, msg, nullptr);
-      NS_ENSURE_TRUE(newEvent, NS_ERROR_OUT_OF_MEMORY);
-      isInputEvent = true;
-      newEvent->eventStructType = NS_POPUP_EVENT;
-      break;
-    }
     case NS_COMMAND_EVENT:
     {
       newEvent = new nsCommandEvent(false, mEvent->userType,
@@ -1062,7 +1053,6 @@ nsDOMEvent::GetScreenCoords(nsPresContext* aPresContext,
 
   if (!aEvent || 
        (aEvent->eventStructType != NS_MOUSE_EVENT &&
-        aEvent->eventStructType != NS_POPUP_EVENT &&
         aEvent->eventStructType != NS_MOUSE_SCROLL_EVENT &&
         aEvent->eventStructType != NS_WHEEL_EVENT &&
         aEvent->eventStructType != NS_TOUCH_EVENT &&
@@ -1121,7 +1111,6 @@ nsDOMEvent::GetClientCoords(nsPresContext* aPresContext,
 
   if (!aEvent ||
       (aEvent->eventStructType != NS_MOUSE_EVENT &&
-       aEvent->eventStructType != NS_POPUP_EVENT &&
        aEvent->eventStructType != NS_MOUSE_SCROLL_EVENT &&
        aEvent->eventStructType != NS_WHEEL_EVENT &&
        aEvent->eventStructType != NS_TOUCH_EVENT &&
diff --git a/content/events/src/nsDOMUIEvent.cpp b/content/events/src/nsDOMUIEvent.cpp
index a94851023b1b..02189970c43a 100644
--- a/content/events/src/nsDOMUIEvent.cpp
+++ b/content/events/src/nsDOMUIEvent.cpp
@@ -111,7 +111,6 @@ nsDOMUIEvent::GetMovementPoint()
 
   if (!mEvent ||
       (mEvent->eventStructType != NS_MOUSE_EVENT &&
-       mEvent->eventStructType != NS_POPUP_EVENT &&
        mEvent->eventStructType != NS_MOUSE_SCROLL_EVENT &&
        mEvent->eventStructType != NS_WHEEL_EVENT &&
        mEvent->eventStructType != NS_DRAG_EVENT &&
@@ -314,7 +313,6 @@ nsDOMUIEvent::GetLayerPoint()
 {
   if (!mEvent ||
       (mEvent->eventStructType != NS_MOUSE_EVENT &&
-       mEvent->eventStructType != NS_POPUP_EVENT &&
        mEvent->eventStructType != NS_MOUSE_SCROLL_EVENT &&
        mEvent->eventStructType != NS_WHEEL_EVENT &&
        mEvent->eventStructType != NS_TOUCH_EVENT &&
diff --git a/content/events/src/nsDOMUIEvent.h b/content/events/src/nsDOMUIEvent.h
index a7360fabd092..ef807fce8d04 100644
--- a/content/events/src/nsDOMUIEvent.h
+++ b/content/events/src/nsDOMUIEvent.h
@@ -37,7 +37,6 @@ public:
   {
     if (!aEvent ||
         (aEvent->eventStructType != NS_MOUSE_EVENT &&
-         aEvent->eventStructType != NS_POPUP_EVENT &&
          aEvent->eventStructType != NS_MOUSE_SCROLL_EVENT &&
          aEvent->eventStructType != NS_WHEEL_EVENT &&
          aEvent->eventStructType != NS_DRAG_EVENT &&
@@ -62,7 +61,6 @@ public:
   {
     if (!aEvent ||
         (aEvent->eventStructType != NS_MOUSE_EVENT &&
-         aEvent->eventStructType != NS_POPUP_EVENT &&
          aEvent->eventStructType != NS_MOUSE_SCROLL_EVENT &&
          aEvent->eventStructType != NS_WHEEL_EVENT &&
          aEvent->eventStructType != NS_DRAG_EVENT &&
diff --git a/content/events/src/nsEventDispatcher.cpp b/content/events/src/nsEventDispatcher.cpp
index b922d709395f..a8f00a3f2c06 100644
--- a/content/events/src/nsEventDispatcher.cpp
+++ b/content/events/src/nsEventDispatcher.cpp
@@ -724,7 +724,6 @@ nsEventDispatcher::CreateEvent(nsPresContext* aPresContext,
       return NS_NewDOMCompositionEvent(
         aDOMEvent, aPresContext, static_cast<nsCompositionEvent*>(aEvent));
     case NS_MOUSE_EVENT:
-    case NS_POPUP_EVENT:
       return NS_NewDOMMouseEvent(aDOMEvent, aPresContext,
                                  static_cast<nsInputEvent*>(aEvent));
     case NS_MOUSE_SCROLL_EVENT:
diff --git a/widget/nsGUIEvent.h b/widget/nsGUIEvent.h
index dfb3c869ddb0..4254d2ec1e65 100644
--- a/widget/nsGUIEvent.h
+++ b/widget/nsGUIEvent.h
@@ -56,7 +56,6 @@ enum nsEventStructType {
 
   // Mouse related events
   NS_MOUSE_EVENT,                    // nsMouseEvent
-  NS_POPUP_EVENT,                    // nsMouseEvent
   NS_MOUSE_SCROLL_EVENT,             // nsMouseScrollEvent
   NS_DRAG_EVENT,                     // nsDragEvent
   NS_WHEEL_EVENT,                    // widget::WheelEvent