diff --git a/deps.edn b/deps.edn
index a766dcc0..fedfe577 100644
--- a/deps.edn
+++ b/deps.edn
@@ -80,7 +80,8 @@
                          io.helins/binf {:mvn/version "1.1.0-beta0"}
                          rm-hull/jasentaa {:mvn/version "0.2.5"}
                          slingshot/slingshot {:mvn/version "0.12.2"}
-                         io.replikativ/hasch {:mvn/version "0.3.7"}}
+                         io.replikativ/hasch {:mvn/version "0.3.7"}
+                         com.grammarly/omniconf {:mvn/version "0.4.3"}}
             :classpath-overrides {org.clojure/clojure nil
                                   org.clojure/spec.alpha nil
                                   org.clojure/core.specs.alpha nil}}
diff --git a/test-resources/lib_tests/babashka/run_all_libtests.clj b/test-resources/lib_tests/babashka/run_all_libtests.clj
index 96ff628e..723ad4ee 100644
--- a/test-resources/lib_tests/babashka/run_all_libtests.clj
+++ b/test-resources/lib_tests/babashka/run_all_libtests.clj
@@ -221,6 +221,8 @@
 (test-namespaces 'hasch.test
                  )
 
+(test-namespaces 'omniconf.core-test)
+
 ;;;; final exit code
 
 (let [{:keys [:test :fail :error] :as m} @status]
diff --git a/test-resources/lib_tests/omniconf/core_test.clj b/test-resources/lib_tests/omniconf/core_test.clj
new file mode 100644
index 00000000..2f832f56
--- /dev/null
+++ b/test-resources/lib_tests/omniconf/core_test.clj
@@ -0,0 +1,36 @@
+(ns omniconf.core-test
+  (:require [clojure.string :as str]
+            [clojure.test :refer [deftest is testing]]
+            [omniconf.core :as cfg])
+  (:import (java.io File)))
+
+(cfg/define
+  {:conf        {:type :file}
+   :foo         {:type     :string
+                 :required true}
+   :the-boolean {:type :boolean}
+   :missing     {:type     :string
+                 :required true}})
+
+(deftest load-cfg-test
+  (testing "multiple config sources"
+    (let [temp-cfg-file (File/createTempFile "cfg" "edn")
+          _             (.deleteOnExit temp-cfg-file)
+          fake-args     ["--conf" (.getAbsolutePath temp-cfg-file)
+                         "--foo" "this will be overridden"]]
+      (do
+        ; put some props in the temp file
+        (spit temp-cfg-file "{:foo \"final value\" :the-boolean false }")
+        ; and set a system property
+        (System/setProperty "the-boolean" "18")
+        (cfg/populate-from-cmd fake-args)
+        (cfg/populate-from-file (cfg/get :conf))
+        (cfg/populate-from-properties)
+        ; cleanup
+        (System/clearProperty "the-boolean")))
+    (is (= "final value" (cfg/get :foo)))
+    (is (= true (cfg/get :the-boolean)))
+    (is (thrown-with-msg? Exception #":missing" (cfg/verify)))
+    (cfg/populate-from-map {:missing "abc"})
+    (let [verify-output (with-out-str (cfg/verify))]
+      (is (every? #(str/includes? verify-output %) [":missing" "abc"])))))