diff --git a/src/reagent/ratom.cljs b/src/reagent/ratom.cljs
index f658645..24a74d8 100644
--- a/src/reagent/ratom.cljs
+++ b/src/reagent/ratom.cljs
@@ -204,7 +204,7 @@
 
 (deftype Reaction [f ^:mutable state ^:mutable dirty? ^:mutable active?
                    ^:mutable watching ^:mutable watches
-                   ^:mutable auto-run on-set on-dispose]
+                   auto-run on-set on-dispose ^:mutable norun?]
   IAtom
   IReactiveAtom
 
@@ -251,7 +251,7 @@
         (set! dirty? (max dirty?
                           (if (identical? oldval newval)
                             maybe-dirty is-dirty)))
-        (if auto-run
+        (if (and auto-run (not norun?))
           (do
             ;; FIXME: is this correct?
             (when (== dirty? maybe-dirty)
@@ -259,7 +259,8 @@
                 (-check-clean this)))
             (when-not (== dirty? clean)
               ((or auto-run run) this)))
-          (-notify-watches this state state))))
+          (when (== old-dirty clean)
+            (-notify-watches this state state)))))
     ;; (when (and active? (not (identical? oldval newval)))
     ;;   (set! dirty? is-dirty)
     ;;   ((or auto-run run) this))
@@ -282,16 +283,16 @@
 
   (-check-clean [this]
     (when (== dirty? maybe-dirty)
-      (let [oldauto auto-run]
-        (set! auto-run nil)
-        (doseq [w watching]
-          (-deref w))
-        (set! auto-run oldauto))
+      (set! norun? true)
+      (doseq [w watching]
+        (-deref w))
+      (set! norun? false)
       (when (== dirty? maybe-dirty)
         (set! dirty? clean))))
 
   IRunnable
   (run [this]
+    (set! norun? true)
     (let [oldstate state
           res (capture-derefed f this)
           derefed (captured this)]
@@ -300,6 +301,7 @@
       (when-not active?
         (when debug (swap! -running inc))
         (set! active? true))
+      (set! norun? false)
       (set! dirty? clean)
       (set! state res)
       (-notify-watches this oldstate state)
@@ -353,7 +355,7 @@
         dirty (if (not active) is-dirty clean)
         reaction (Reaction. f nil dirty active
                             nil nil
-                            runner on-set on-dispose)]
+                            runner on-set on-dispose false)]
     (when-not (nil? derefed)
       (when debug (swap! -running inc))
       (-update-watching reaction derefed))
diff --git a/test/reagenttest/testcursor.cljs b/test/reagenttest/testcursor.cljs
index 5c08736..ac73d31 100644
--- a/test/reagenttest/testcursor.cljs
+++ b/test/reagenttest/testcursor.cljs
@@ -31,7 +31,7 @@
     (is (= @out 2))
     (reset! start 1)
     (is (= @out 3))
-    (is (= @count 4))
+    (is (= @count 2))
     (dispose const)
     (is (= @start-base {:a {:b {:c 1}}}))
     (is (= (running) runs))))
diff --git a/test/reagenttest/testratom.cljs b/test/reagenttest/testratom.cljs
index 0f91a40..8df5eb2 100644
--- a/test/reagenttest/testratom.cljs
+++ b/test/reagenttest/testratom.cljs
@@ -42,7 +42,7 @@
     (is (= @out 2))
     (reset! start 1)
     (is (= @out 3))
-    (is (= @count 4))
+    (is (= @count 2))
     (dispose const)
     (is (= (running) runs))))
 
diff --git a/test/reagenttest/testreagent.cljs b/test/reagenttest/testreagent.cljs
index 45d3d66..d7d94d9 100644
--- a/test/reagenttest/testreagent.cljs
+++ b/test/reagenttest/testreagent.cljs
@@ -122,13 +122,13 @@
           (is (= 1 @ran))
           (r/flush)
           (is (found-in #"val 1" div))
-          (is (= 2 @ran))
+          (is (= 2 @ran) "ran once more")
 
           ;; should not be rendered
           (reset! val 1)
           (r/flush)
           (is (found-in #"val 1" div))
-          (is (= 2 @ran))))
+          (is (= 2 @ran) "did not run")))
       (is (= runs (running)))
       (is (= 2 @ran)))))