diff --git a/src/duct/core.clj b/src/duct/core.clj
index 8f2f153..3bc6a4e 100644
--- a/src/duct/core.clj
+++ b/src/duct/core.clj
@@ -110,7 +110,8 @@
   (merge
    {'duct/env      env/env
     'duct/include  (make-include readers)
-    'duct/resource resource}
+    'duct/resource resource
+    'duct/regex    re-pattern}
    readers))
 
 (defn read-config
@@ -119,7 +120,7 @@
 
   #duct/env
   : an environment variable, see [[duct.core.env/env]]
-  
+
   #duct/include
   : substitute for a configuration on the classpath
 
diff --git a/test/duct/core_test.clj b/test/duct/core_test.clj
index 5d58b14..fa8b130 100644
--- a/test/duct/core_test.clj
+++ b/test/duct/core_test.clj
@@ -48,12 +48,15 @@
     {::a {:x 1}}           {::a (ig/refset ::b)}         {::a (ig/refset ::b)}))
 
 (deftest test-read-config
-  (is (= (core/read-config (io/resource "duct/readers.edn") {'custom/bar (fn [x] {:x x})})
-         {:foo/a {:x "bar"}
-          :foo/b {:bar/a {:x 1}, :bar/b (ig/ref :bar/a) :bar/c {:baz/a {:x 1}}}
-          :foo/c (core/resource "duct/config.edn")
-          :foo/d (ig/ref :foo/a)
-          :foo/e (ig/refset :foo/b)})))
+  (let [config (core/read-config (io/resource "duct/readers.edn") {'custom/bar (fn [x] {:x x})})]
+    (is (= (dissoc config :foo/f)
+           {:foo/a {:x "bar"}
+            :foo/b {:bar/a {:x 1}, :bar/b (ig/ref :bar/a) :bar/c {:baz/a {:x 1}}}
+            :foo/c (core/resource "duct/config.edn")
+            :foo/d (ig/ref :foo/a)
+            :foo/e (ig/refset :foo/b)}))
+    (is (= (.pattern (:foo/f config))
+           "baz"))))
 
 (defmethod ig/init-key ::foo [_ {:keys [x]}]
   #(update % ::x (fnil conj []) x))
diff --git a/test/duct/readers.edn b/test/duct/readers.edn
index c93fcfb..dc691ee 100644
--- a/test/duct/readers.edn
+++ b/test/duct/readers.edn
@@ -2,4 +2,5 @@
  :foo/b #duct/include "duct/config.edn"
  :foo/c #duct/resource "duct/config.edn"
  :foo/d #ig/ref :foo/a
- :foo/e #ig/refset :foo/b}
+ :foo/e #ig/refset :foo/b
+ :foo/f #duct/regex "baz"}