diff --git a/leiningen-core/src/leiningen/core/user.clj b/leiningen-core/src/leiningen/core/user.clj
index 58044a23..9d8662a2 100644
--- a/leiningen-core/src/leiningen/core/user.clj
+++ b/leiningen-core/src/leiningen/core/user.clj
@@ -6,10 +6,15 @@
             [leiningen.core.utils :as utils])
   (:import (java.util.regex Pattern)))
 
+(defn getenv
+  "Wrap System/getenv for testing purposes."
+  [name]
+  (System/getenv name))
+
 (defn leiningen-home
   "Return full path to the user's Leiningen home directory."
   []
-  (let [lein-home (System/getenv "LEIN_HOME")
+  (let [lein-home (getenv "LEIN_HOME")
         lein-home (or (and lein-home (io/file lein-home))
                       (io/file (System/getProperty "user.home") ".lein"))]
     (.getAbsolutePath (doto lein-home .mkdirs))))
@@ -68,7 +73,7 @@
 (defn gpg-program
   "Lookup the gpg program to use, defaulting to 'gpg'"
   []
-  (or (System/getenv "LEIN_GPG") "gpg"))
+  (or (getenv "LEIN_GPG") "gpg"))
 
 (defn gpg
   "Shells out to (gpg-program) with the given arguments"
@@ -109,23 +114,27 @@
                 cred))))
 
 (defn- resolve-credential
+  "Resolve key-value pair from result into a credential, updating result."
   [source-settings result [k v]]
   (letfn [(resolve [v]
             (cond (= :env v)
-                  (System/getenv (str "LEIN_" (str/upper-case (name k))))
+                  (getenv (str "LEIN_" (str/upper-case (name k))))
 
                   (and (keyword? v) (= "env" (namespace v)))
-                  (System/getenv (str/upper-case (name v)))
+                  (getenv (str/upper-case (name v)))
 
                   (= :gpg v)
                   (get (match-credentials source-settings (credentials)) k)
 
-                  (coll? v)
+                  (coll? v) ;; collection of places to look
                   (->> (map resolve v)
                        (remove nil?)
                        first)
+
                   :else v))]
-    (assoc result k (resolve v))))
+    (if (#{:username :password :passphrase :private-key-file} k)
+      (assoc result k (resolve v))
+      (assoc result k v))))
 
 (defn resolve-credentials
   "Applies credentials from the environment or ~/.lein/credentials.clj.gpg
diff --git a/leiningen-core/test/leiningen/core/test/user.clj b/leiningen-core/test/leiningen/core/test/user.clj
new file mode 100644
index 00000000..4d01871a
--- /dev/null
+++ b/leiningen-core/test/leiningen/core/test/user.clj
@@ -0,0 +1,38 @@
+(ns leiningen.core.test.user
+  (:use clojure.test
+        leiningen.core.user))
+
+(deftest resolving-repo-creds
+  (with-redefs [credentials-fn (constantly {#"^https://clojars\.org/.*"
+                                            {:username "u" :password "p"
+                                             :passphrase "looooong"
+                                             :private-key-file "./somewhere"}})]
+    (testing "Literal creds unmolested"
+      (is (= (resolve-credentials {:url "https://clojars.org/repo"
+                                   :username "easily" :password "stolen"})
+             {:url "https://clojars.org/repo"
+              :username "easily" :password "stolen"})))
+    (testing "Lookup in enivronment"
+      (with-redefs [getenv {"LEIN_USERNAME" "flynn"
+                            "CUSTOMENV" "flotilla"}]
+        (is (= (resolve-credentials {:url "https://clojars.org/repo"
+                                     :username :env
+                                     :password :env/customenv})
+               {:url "https://clojars.org/repo"
+                :username "flynn" :password "flotilla"}))))
+    (testing "Check multiple locations"
+      (with-redefs [getenv {"LEIN_USERNAME" "flynn"
+                            "CUSTOMENV" "flotilla"}]
+        (is (= (resolve-credentials {:url "https://clojars.org/repo"
+                                     :username [:gpg :env]
+                                     :password [:env/customenv :gpg]})
+               {:url "https://clojars.org/repo"
+                :username "u" :password "flotilla"}))))
+    (testing "Custom keys unmolested (and :creds expanded)"
+      (is (= (resolve-credentials {:url "https://clojars.org/repo"
+                                   :creds :gpg
+                                   :foo [:gpg "0x00D85767"]})
+             {:url "https://clojars.org/repo"
+              :username "u" :password "p"
+              :passphrase "looooong" :private-key-file "./somewhere"
+              :foo [:gpg "0x00D85767"]})))))