diff --git a/devtools/client/animationinspector/animation-controller.js b/devtools/client/animationinspector/animation-controller.js
index e5ad109223a..cc68a600d72 100644
--- a/devtools/client/animationinspector/animation-controller.js
+++ b/devtools/client/animationinspector/animation-controller.js
@@ -144,6 +144,13 @@ var AnimationsController = {
     // Expose actor capabilities.
     this.traits = yield getServerTraits(target);
 
+    // We want to handle animation mutation events synchronously to avoid race
+    // conditions when there are many rapid mutations. So when a mutation occurs
+    // and animations are removed, we don't release the corresponding actors
+    // in a blocking way, we just release asynchronously and don't wait for
+    // completion, but instead store the promise in this array.
+    this.nonBlockingPlayerReleases = [];
+
     if (this.destroyed) {
       console.warn("Could not fully initialize the AnimationsController");
       return;
@@ -176,6 +183,9 @@ var AnimationsController = {
     yield this.destroyAnimationPlayers();
     this.nodeFront = null;
 
+    // Finish releasing players that haven't been released yet.
+    yield Promise.all(this.nonBlockingPlayerReleases);
+
     if (this.animationsFront) {
       this.animationsFront.destroy();
       this.animationsFront = null;
@@ -331,7 +341,7 @@ var AnimationsController = {
     }
   }),
 
-  onAnimationMutations: Task.async(function*(changes) {
+  onAnimationMutations: function(changes) {
     // Insert new players into this.animationPlayers when new animations are
     // added.
     for (let {type, player} of changes) {
@@ -340,7 +350,8 @@ var AnimationsController = {
       }
 
       if (type === "removed") {
-        yield player.release();
+        // Don't wait for the release request to complete, we can do that later.
+        this.nonBlockingPlayerReleases.push(player.release());
         let index = this.animationPlayers.indexOf(player);
         this.animationPlayers.splice(index, 1);
       }
@@ -348,7 +359,7 @@ var AnimationsController = {
 
     // Let the UI know the list has been updated.
     this.emit(this.PLAYERS_UPDATED_EVENT, this.animationPlayers);
-  }),
+  },
 
   /**
    * Get the latest known current time of document.timeline.