diff --git a/deps.edn b/deps.edn
index 8a39f0b..69a12a1 100644
--- a/deps.edn
+++ b/deps.edn
@@ -11,6 +11,10 @@
      :sha "cb96e80f6f3d3b307c59cbeb49bb0dcb3a2a780b"}}
    :extra-paths ["test"]
    :main-opts ["-m" "cognitect.test-runner"]}
+  :kaocha
+  {:extra-deps
+   {lambdaisland/kaocha {:mvn/version "1.0.632"}}
+   :main-opts ["-m" "kaocha.runner"]}
   :test-pod
   {:paths ["src" "test-pod"]
    :main-opts ["-m" "pod.test-pod"]}}}
diff --git a/script/test b/script/test
index 576735a..6aab3b3 100755
--- a/script/test
+++ b/script/test
@@ -1,4 +1,7 @@
 #!/usr/bin/env bash
 
 clojure -A:test -n babashka.pods.jvm-test
+#clojure -A:test:kaocha --focus babashka.pods.jvm-test
+
 clojure -A:sci:test -n babashka.pods.sci-test
+#clojure -A:sci:test:kaocha --focus babashka.pods.sci-test
diff --git a/src/babashka/pods.clj b/src/babashka/pods.clj
index 2450acf..54e32bd 100644
--- a/src/babashka/pods.clj
+++ b/src/babashka/pods.clj
@@ -9,5 +9,6 @@
   ([pod-id] (unload-pod pod-id {}))
   ([pod-id opts] (jvm/unload-pod pod-id opts)))
 
-(defn invoke [pod-id sym args opts]
-  (jvm/invoke pod-id sym args opts))
+(defn invoke
+  ([pod-id sym args] (invoke pod-id sym args {}))
+  ([pod-id sym args opts] (jvm/invoke pod-id sym args opts)))
diff --git a/src/babashka/pods/impl.clj b/src/babashka/pods/impl.clj
index 57944a5..2a637ee 100644
--- a/src/babashka/pods/impl.clj
+++ b/src/babashka/pods/impl.clj
@@ -119,8 +119,7 @@
                          "op" "invoke"
                          "var" (str pod-var)
                          "args" (write-fn args)})]
-    ;; see: https://blog.jakubholy.net/2019/core-async-error-handling/
-    (cond handlers handlers
+    (cond handlers nil
           :else (let [v @chan]
                   (if (instance? Throwable v)
                     (throw v)
@@ -143,6 +142,12 @@
       (doseq [[ns-name _] (:namespaces pod)]
         (rns ns-name)))))
 
+(def next-pod-id
+  (let [counter (atom 0)]
+    (fn []
+      (let [[o _] (swap-vals! counter inc)]
+        o))))
+
 (defn load-pod
   ([pod-spec] (load-pod pod-spec nil))
   ([pod-spec {:keys [:remove-ns]}]
@@ -207,8 +212,7 @@
 
 (defn invoke-public [pod-id fn-sym args opts]
   (let [pod (lookup-pod pod-id)]
-    (invoke pod fn-sym args opts)
-    nil))
+    (invoke pod fn-sym args opts)))
 
 (defn unload-pod [pod-id]
   (destroy pod-id))
diff --git a/src/babashka/pods/jvm.clj b/src/babashka/pods/jvm.clj
index 3f9483d..03a06b6 100644
--- a/src/babashka/pods/jvm.clj
+++ b/src/babashka/pods/jvm.clj
@@ -24,5 +24,6 @@
   ([pod-id _opts]
    (impl/unload-pod pod-id)))
 
-(defn invoke [pod-id sym args opts]
-  (impl/invoke-public pod-id sym args opts))
+(defn invoke
+  ([pod-id sym args] (invoke pod-id sym args {}))
+  ([pod-id sym args opts] (impl/invoke-public pod-id sym args opts)))
diff --git a/src/babashka/pods/sci.clj b/src/babashka/pods/sci.clj
index 7545a19..dcd902f 100644
--- a/src/babashka/pods/sci.clj
+++ b/src/babashka/pods/sci.clj
@@ -32,5 +32,6 @@
   ([pod-id _opts]
    (impl/unload-pod pod-id)))
 
-(defn invoke [pod-id sym args opts]
-  (impl/invoke-public pod-id sym args opts))
+(defn invoke
+  ([pod-id sym args] (invoke pod-id sym args {}))
+  ([pod-id sym args opts] (impl/invoke-public pod-id sym args opts)))
diff --git a/test-resources/test_program.clj b/test-resources/test_program.clj
index 1c9c8c9..4cb4f52 100644
--- a/test-resources/test_program.clj
+++ b/test-resources/test_program.clj
@@ -23,13 +23,16 @@
 (pod/do-twice (prn :foo))
 
 (def callback-result (promise))
-(pods/invoke "pod.test-pod" 'pod.test-pod/add-sync [1 2]
+(pods/invoke pod-id 'pod.test-pod/add-sync [1 2]
              {:handlers {:success
                          (fn [value]
                            (deliver callback-result value))}})
 
+(def sync-invoke
+  (pods/invoke pod-id 'pod.test-pod/add-sync [1 2]))
+
 (def error-result (promise))
-(pods/invoke "pod.test-pod" 'pod.test-pod/add-sync ["1" 2]
+(pods/invoke pod-id 'pod.test-pod/add-sync ["1" 2]
              {:handlers
               {:error (fn [m]
                         (deliver error-result m))}})
@@ -45,6 +48,7 @@
  pod-ns-name
  assoc-result
  add-result
+ sync-invoke
  @stream-results
  ex-result
  nil-result
diff --git a/test/babashka/pods/test_common.clj b/test/babashka/pods/test_common.clj
index 1a9c928..c5efe1d 100644
--- a/test/babashka/pods/test_common.clj
+++ b/test/babashka/pods/test_common.clj
@@ -9,6 +9,7 @@
            pod.test-pod
            {:a 1, :b 2}
            6
+           3
            [1 2 3 4 5 6 7 8 9]
            "Illegal arguments / {:args (1 2 3)}"
            nil