diff --git a/image/FrameAnimator.cpp b/image/FrameAnimator.cpp
index 076f884dab48..d7d1312cde0e 100644
--- a/image/FrameAnimator.cpp
+++ b/image/FrameAnimator.cpp
@@ -57,9 +57,11 @@ AnimationState::UpdateStateInternal(LookupResult& aResult,
     // no frames yet, but a decoder is or will be working on it.
     mDiscarded = false;
     mIsCurrentlyDecoded = false;
+    mHasRequestedDecode = true;
   } else {
     MOZ_ASSERT(aResult.Type() == MatchType::EXACT);
     mDiscarded = false;
+    mHasRequestedDecode = true;
 
     // If mHasBeenDecoded is true then we know the true total frame count and
     // we can use it to determine if we have all the frames now so we know if
@@ -99,7 +101,7 @@ AnimationState::UpdateStateInternal(LookupResult& aResult,
       mCompositedFrameInvalid = false;
     } else if (aResult.Type() == MatchType::NOT_FOUND ||
                aResult.Type() == MatchType::PENDING) {
-      if (mHasBeenDecoded) {
+      if (mHasRequestedDecode) {
         MOZ_ASSERT(gfxPrefs::ImageMemAnimatedDiscardable());
         mCompositedFrameInvalid = true;
       }
@@ -209,7 +211,7 @@ FrameAnimator::GetCurrentImgFrameEndTime(AnimationState& aState,
     GetTimeoutForFrame(aState, aFrames, aState.mCurrentAnimationFrameIndex);
 
   if (timeout.isNothing()) {
-    MOZ_ASSERT(aState.GetHasBeenDecoded() && !aState.GetIsCurrentlyDecoded());
+    MOZ_ASSERT(aState.GetHasRequestedDecode() && !aState.GetIsCurrentlyDecoded());
     return Nothing();
   }
 
@@ -416,7 +418,7 @@ FrameAnimator::RequestRefresh(AnimationState& aState,
     GetCurrentImgFrameEndTime(aState, result.Surface());
   if (currentFrameEndTime.isNothing()) {
     MOZ_ASSERT(gfxPrefs::ImageMemAnimatedDiscardable());
-    MOZ_ASSERT(aState.GetHasBeenDecoded() && !aState.GetIsCurrentlyDecoded());
+    MOZ_ASSERT(aState.GetHasRequestedDecode() && !aState.GetIsCurrentlyDecoded());
     MOZ_ASSERT(aState.mCompositedFrameInvalid);
     // Nothing we can do but wait for our previous current frame to be decoded
     // again so we can determine what to do next.
@@ -465,7 +467,7 @@ FrameAnimator::GetCompositedFrame(AnimationState& aState)
 
   if (aState.mCompositedFrameInvalid) {
     MOZ_ASSERT(gfxPrefs::ImageMemAnimatedDiscardable());
-    MOZ_ASSERT(aState.GetHasBeenDecoded());
+    MOZ_ASSERT(aState.GetHasRequestedDecode());
     MOZ_ASSERT(!aState.GetIsCurrentlyDecoded());
     if (result.Type() == MatchType::NOT_FOUND) {
       return result;
@@ -512,7 +514,7 @@ FrameAnimator::GetTimeoutForFrame(AnimationState& aState,
     return Some(data.mTimeout);
   }
 
-  MOZ_ASSERT(aState.mHasBeenDecoded && !aState.mIsCurrentlyDecoded);
+  MOZ_ASSERT(aState.mHasRequestedDecode && !aState.mIsCurrentlyDecoded);
   return Nothing();
 }
 
diff --git a/image/FrameAnimator.h b/image/FrameAnimator.h
index b8136872292a..9a5fa39f7416 100644
--- a/image/FrameAnimator.h
+++ b/image/FrameAnimator.h
@@ -34,6 +34,7 @@ public:
     , mFirstFrameTimeout(FrameTimeout::FromRawMilliseconds(0))
     , mAnimationMode(aAnimationMode)
     , mHasBeenDecoded(false)
+    , mHasRequestedDecode(false)
     , mIsCurrentlyDecoded(false)
     , mCompositedFrameInvalid(false)
     , mDiscarded(false)
@@ -66,6 +67,11 @@ public:
    */
   bool GetHasBeenDecoded() { return mHasBeenDecoded; }
 
+  /**
+   * Returns true if this image has ever requested a decode before.
+   */
+  bool GetHasRequestedDecode() { return mHasRequestedDecode; }
+
   /**
    * Returns true if this image has been discarded and a decoded has not yet
    * been created to redecode it.
@@ -221,6 +227,9 @@ private:
   //! Whether this image has been decoded at least once.
   bool mHasBeenDecoded;
 
+  //! Whether this image has ever requested a decode.
+  bool mHasRequestedDecode;
+
   //! Whether this image is currently fully decoded.
   bool mIsCurrentlyDecoded;