diff --git a/projects/main/src/taoensso/telemere.cljc b/projects/main/src/taoensso/telemere.cljc
index a507dfd..d83b39d 100644
--- a/projects/main/src/taoensso/telemere.cljc
+++ b/projects/main/src/taoensso/telemere.cljc
@@ -332,17 +332,21 @@
      See `uncaught->handler!` and `error!` for details."
      {:arglists (impl/signal-arglists :uncaught->error!)}
      [& args]
-     (let [msg-form ["Uncaught Throwable on thread: " `(.getName ~(with-meta '__thread {:tag 'java.lang.Thread}))]
+     (let [msg-form ["Uncaught Throwable on thread:" `(.getName ~(with-meta '__thread-arg {:tag 'java.lang.Thread}))]
            opts
            (impl/signal-opts `uncaught->error! (enc/get-source &form &env)
              {:kind :error, :level :error, :msg msg-form}
-             :error :id :dsc (into ['__throwable] args))]
+             :error :id :dsc (into ['__throwable-arg] args))]
 
        `(uncaught->handler!
-          (fn [~'__thread ~'__throwable]
+          (fn [~'__thread-arg ~'__throwable-arg]
             (impl/signal! ~opts))))))
 
-(comment (macroexpand '(uncaught->error! ::my-id)))
+(comment
+  (macroexpand '(uncaught->error! ::uncaught))
+  (do
+    (uncaught->error! ::uncaught)
+    (enc/threaded :user (/ 1 0))))
 
 #?(:clj
    (defn uncaught->handler!
@@ -352,9 +356,10 @@
      See also `uncaught->error!`."
      [handler]
      (Thread/setDefaultUncaughtExceptionHandler
-       (reify   Thread$UncaughtExceptionHandler
-         (uncaughtException [_ thread throwable]
-           (handler            thread throwable))))
+       (when handler ; falsey to remove
+         (reify   Thread$UncaughtExceptionHandler
+           (uncaughtException [_ thread throwable]
+             (handler            thread throwable)))))
      nil))
 
 ;;;; Interop
diff --git a/projects/main/test/taoensso/telemere_tests.cljc b/projects/main/test/taoensso/telemere_tests.cljc
index a8a63df..1b4f479 100644
--- a/projects/main/test/taoensso/telemere_tests.cljc
+++ b/projects/main/test/taoensso/telemere_tests.cljc
@@ -671,6 +671,16 @@
   (testing "Signals in go macros"
     [(async/go (tel/log! "hello"))]))
 
+#?(:clj
+   (deftest _uncaught->handler!
+     (let [p (promise)]
+       [(do (tel/add-handler! ::p (fn ([]) ([sig] (p sig))) {}) :add-handler)
+        (is (nil? (tel/uncaught->error! ::uncaught)))
+        (do (enc/threaded :user (throw ex1)) :run-thread)
+        (is (sm? (deref p 2000 nil) {:kind :error, :level :error, :id ::uncaught, :error ex1}))
+        (is (nil? (tel/uncaught->error! nil)))
+        (do (tel/remove-handler! ::p) :remove-handler)])))
+
 ;;;; Interop
 
 (comment (def ^org.slf4j.Logger sl (org.slf4j.LoggerFactory/getLogger "my.class")))