diff --git a/src/play_clj/core_utils.clj b/src/play_clj/core_utils.clj
index b0d8645..c1d7c45 100644
--- a/src/play_clj/core_utils.clj
+++ b/src/play_clj/core_utils.clj
@@ -100,10 +100,15 @@ specified path.
 
 (defn ^:private create-and-add-timer!
   [{:keys [update-fn!] :as screen} id]
-  (some-> (get-in screen [:timers id]) .stop)
-  (let [timer (timer*)]
-    (update-fn! assoc-in [[:timers id] timer])
-    timer))
+  ; remove timer if it already exists
+  (when-let [old-timer (get-in screen [:timers id])]
+    (.stop old-timer)
+    (some-> u/*timers* (swap! disj old-timer)))
+  ; create timer, add to screen map, and return it
+  (let [new-timer (timer*)]
+    (update-fn! assoc-in [[:timers id] new-timer])
+    (some-> u/*timers* (swap! conj new-timer))
+    new-timer))
 
 (defn add-timer!
   "Returns a [Timer](http://libgdx.badlogicgames.com/nightlies/docs/api/com/badlogic/gdx/utils/Timer.html)
diff --git a/src/play_clj/utils.clj b/src/play_clj/utils.clj
index a2fd296..f3d2b72 100644
--- a/src/play_clj/utils.clj
+++ b/src/play_clj/utils.clj
@@ -5,15 +5,6 @@
 
 ; misc
 
-(def ^:dynamic *asset-manager* nil)
-
-(defn load-asset
-  [path type]
-  (when-let [^AssetManager am *asset-manager*]
-    (.load am path type)
-    (.finishLoading am)
-    (.get am path type)))
-
 (defn throw-key-not-found
   [k]
   (throw (Exception. (str "The keyword " k " is not found."))))
@@ -25,6 +16,32 @@
         (throw-key-not-found k))
     obj))
 
+; assets
+
+(def ^:dynamic *asset-manager* nil)
+
+(defn load-asset
+  [path type]
+  (when-let [^AssetManager am *asset-manager*]
+    (.load am path type)
+    (.finishLoading am)
+    (.get am path type)))
+
+; timers
+
+(def ^:dynamic *timers* nil)
+
+(defn track-timers!
+  []
+  (intern 'play-clj.utils '*timers* (atom #{})))
+
+(defn stop-timers!
+  []
+  (when *timers*
+    (doseq [t (deref *timers*)]
+      (.stop t))
+    (reset! *timers* #{})))
+
 ; converting keys
 
 (def ^:const main-package "com.badlogic.gdx")