diff --git a/doc/img/cljs-ns-reload.png b/doc/img/cljs-ns-reload.png
new file mode 100644
index 0000000..e71c2cf
Binary files /dev/null and b/doc/img/cljs-ns-reload.png differ
diff --git a/src/mount/core.cljc b/src/mount/core.cljc
index 795075d..d872eb3 100644
--- a/src/mount/core.cljc
+++ b/src/mount/core.cljc
@@ -3,7 +3,7 @@
                     [clojure.string :as s])
      :cljs (:require [mount.tools.macro :as macro]))
   #?(:cljs (:require-macros [mount.core]
-                            [mount.tools.macro :refer [on-error throw-runtime]])))
+                            [mount.tools.macro :refer [if-clj on-error throw-runtime]])))
 
 (defonce ^:private -args (atom :no-args))                  ;; mostly for command line args and external files
 (defonce ^:private state-seq (atom 0))
@@ -51,7 +51,9 @@
   [state]
   (when-let [{:keys [stop] :as up} (@running state)]
     (when stop
-      (prn (str "<< stopping.. " state " (namespace was recompiled)"))
+      (let [note (str "<< stopping.. " state " (namespace was recompiled)")]
+      #?(:clj (prn note)
+         :cljs (.log js/console note)))
       (stop))
     (swap! running dissoc state)))
 
@@ -86,7 +88,7 @@
 
 (defn- up [state {:keys [start stop resume status] :as current} done]
   (when-not (:started status)
-    (let [s (on-error (str "could not start [" state "] due to") 
+    (let [s (on-error (str "could not start [" state "] due to")
                       (if (:suspended status)
                         (record! state resume done)
                         (record! state start done)))]
@@ -129,6 +131,14 @@
         (up name state (atom #{})))
       @inst)))
 
+#?(:clj
+    (defn log [msg]
+      (prn msg)))
+
+#?(:cljs
+    (defn log [msg]
+      (.log js/console msg)))
+
 #?(:clj
     (defmacro defstate [state & body]
       (let [[state params] (macro/name-with-attributes state body)
@@ -150,7 +160,7 @@
                    restart?# ((~'var mount.core/cleanup-if-dirty) ~state-name)]
                ((~'var mount.core/update-meta!) [~state-name] meta#)
                (~'when restart?#
-                 (~'prn (str ">> starting.. " ~state-name " (namespace was recompiled)"))
+                 (log (~'str ">> starting.. " ~state-name " (namespace was recompiled)"))
                  ((~'var mount.core/up) ~state-name meta# (~'atom #{})))
                (~'var ~state)))))))
 
diff --git a/src/mount/tools/macro.cljc b/src/mount/tools/macro.cljc
index f7449d0..dc46e24 100644
--- a/src/mount/tools/macro.cljc
+++ b/src/mount/tools/macro.cljc
@@ -1,19 +1,26 @@
 (ns mount.tools.macro
   #?(:cljs (:require-macros [mount.tools.macro])))
 
+#?(:clj
+    (defmacro if-clj [then else]
+      (if (-> &env :ns not)
+        then
+        else)))
+
 #?(:clj
     (defmacro on-error [msg f]
-      `(try
-         ~f
-         (catch #?(:clj Throwable
-                        :cljs :default) t#
-           (throw #?(:clj (RuntimeException. ~msg t#)
-                          :cljs (js/Error (str ~msg (.-stack t#)))))))))
+      `(if-clj
+         (try ~f
+              (catch Throwable t#
+                (throw (RuntimeException. ~msg t#))))
+         (try ~f
+              (catch :default t#
+                (throw (~'str ~msg " " t#)))))))
 
 #?(:clj
     (defmacro throw-runtime [msg]
-      `(throw #?(:clj (RuntimeException. ~msg)
-                      :cljs (js/Error (str ~msg))))))
+      `(throw (if-clj (RuntimeException. ~msg)
+                      (~'str ~msg)))))
 
 ;; this is a one to one copy from https://github.com/clojure/tools.macro
 ;; to avoid a lib dependency for a single function