diff --git a/gfx/layers/apz/src/AsyncPanZoomAnimation.h b/gfx/layers/apz/src/AsyncPanZoomAnimation.h
index 48d4dd4794f..fd0574001a8 100644
--- a/gfx/layers/apz/src/AsyncPanZoomAnimation.h
+++ b/gfx/layers/apz/src/AsyncPanZoomAnimation.h
@@ -22,8 +22,7 @@ class AsyncPanZoomAnimation {
   NS_INLINE_DECL_THREADSAFE_REFCOUNTING(AsyncPanZoomAnimation)
 
 public:
-  explicit AsyncPanZoomAnimation(const TimeDuration& aRepaintInterval =
-                                 TimeDuration::Forever())
+  explicit AsyncPanZoomAnimation(const TimeDuration& aRepaintInterval)
     : mRepaintInterval(aRepaintInterval)
   { }
 
diff --git a/gfx/layers/apz/src/AsyncPanZoomController.cpp b/gfx/layers/apz/src/AsyncPanZoomController.cpp
index 6e735fbd225..5b89a39f278 100644
--- a/gfx/layers/apz/src/AsyncPanZoomController.cpp
+++ b/gfx/layers/apz/src/AsyncPanZoomController.cpp
@@ -592,7 +592,8 @@ class ZoomAnimation: public AsyncPanZoomAnimation {
 public:
   ZoomAnimation(CSSPoint aStartOffset, CSSToParentLayerScale2D aStartZoom,
                 CSSPoint aEndOffset, CSSToParentLayerScale2D aEndZoom)
-    : mTotalDuration(TimeDuration::FromMilliseconds(gfxPrefs::APZZoomAnimationDuration()))
+    : AsyncPanZoomAnimation(TimeDuration::Forever())
+    , mTotalDuration(TimeDuration::FromMilliseconds(gfxPrefs::APZZoomAnimationDuration()))
     , mStartOffset(aStartOffset)
     , mStartZoom(aStartZoom)
     , mEndOffset(aEndOffset)
@@ -650,7 +651,8 @@ private:
 class OverscrollAnimation: public AsyncPanZoomAnimation {
 public:
   explicit OverscrollAnimation(AsyncPanZoomController& aApzc, const ParentLayerPoint& aVelocity)
-    : mApzc(aApzc)
+    : AsyncPanZoomAnimation(TimeDuration::Forever())
+    , mApzc(aApzc)
   {
     mApzc.mX.SetVelocity(aVelocity.x);
     mApzc.mY.SetVelocity(aVelocity.y);