diff --git a/doc/GPG.md b/doc/GPG.md
index 8f432b91..f71a5d91 100644
--- a/doc/GPG.md
+++ b/doc/GPG.md
@@ -16,12 +16,14 @@
   - [How Leiningen uses GPG](#how-leiningen-uses-gpg)
     - [Signing a file](#signing-a-file)
     - [Overriding the gpg defaults](#overriding-the-gpg-defaults)
+    - [Setting the gpg passphrase for unattended deploys](#setting-the-gpg-passphrase-for-unattended-deploys)
   - [Troubleshooting](#troubleshooting)
     - [Debian based distributions](#debian-based-distributions-1)
       - [gpg: can't query passphrase in batch mode](#gpg-cant-query-passphrase-in-batch-mode)
     - [Mac OSX](#mac-osx)
       - [Unable to get GPG installed via Homebrew and OSX Keychain to work](#unable-to-get-gpg-installed-via-homebrew-and-osx-keychain-to-work)
       - [GPG doesn't ask for a passphrase](#gpg-doesnt-ask-for-a-passphrase)
+      - [gpg: decryption failed: secret key not available](#gpg-decryption-failed-secret-key-not-available)
     - [GPG prompts for passphrase but does not work with Leiningen](#gpg-prompts-for-passphrase-but-does-not-work-with-leiningen)
 
 <!-- END doctoc generated TOC please keep comment here to allow auto update -->
@@ -250,6 +252,33 @@ repository specification in your project definition:
          ["snapshots" "https://blueant.com/archiva/internal/snapshots"]]
        ...)
 
+### Setting the gpg passphrase for unattended deploys
+
+It's also possible to provide the passphrase required to unlock your
+keyring. This is meant only for unattended deploys, for example in a
+continuous integration system like Travis CI or CircleCI or Jenkins. 
+
+Passphrase can be configured in the environment: 
+
+    (defproject ham-biscuit "0.1.0"
+       ...
+       :signing {:gpg-key "bob@bobsons.net"
+                 :gpg-passphrase :env/gpgpass} ;; looks up GPGPASS from env
+       ...)
+
+In your CI service your gpg keyring will need to be encrypted and
+injected into the build, and the passphrase likewise encrypted such that
+the environment variable is visible only to the build.
+
+For testing purposes the pasphrase can also be set as a string literal
+but this is strongly discouraged in any production usage.
+
+    (defproject ham-biscuit "0.1.0"
+       ...
+       :signing {:gpg-key "bob@bobsons.net"
+                 :gpg-passphrase "my-passphrase-in-the-clear"}
+       ...)
+
 ## Troubleshooting
 
 ### Debian based distributions
diff --git a/leiningen-core/src/leiningen/core/user.clj b/leiningen-core/src/leiningen/core/user.clj
index a6bde804..8abd4731 100644
--- a/leiningen-core/src/leiningen/core/user.clj
+++ b/leiningen-core/src/leiningen/core/user.clj
@@ -2,7 +2,6 @@
   "Functions exposing user-level configuration."
   (:require [clojure.java.io :as io]
             [clojure.string :as str]
-            [clojure.java.shell :as shell]
             [leiningen.core.utils :as utils])
   (:import (com.hypirion.io Pipe)
            (org.apache.commons.io.output TeeOutputStream)
@@ -104,9 +103,14 @@
   [env]
   (into-array String (map (fn [[k v]] (str (name k) "=" v)) env)))
 
-(defn gpg
-  "Shells out to (gpg-program) with the given arguments"
-  [& args]
+(defn gpg-with-passphrase
+  "Shells out to (gpg-program) with the given arguments and, if
+  passphrase is not nil, sends the passphrase on stdin for unattended
+  operations such as signing artifacts for deployment. When a passphrase
+  is provided the caller must include the following args
+  [\"--passphrase-fd\" \"0\" \"--pinentry-mode\" \"loopback\"]
+  along with whatever other args are needed for the gpg command."
+  [passphrase & args]
   (try
     (let [proc-env (as-env-strings (get-english-env))
           proc-args (into-array String (concat [(gpg-program)] args))
@@ -114,10 +118,15 @@
       (.addShutdownHook (Runtime/getRuntime)
                         (Thread. (fn [] (.destroy proc))))
       (with-open [out (.getInputStream proc)
+                  err (.getErrorStream proc)
                   err-output (ByteArrayOutputStream.)]
-        (let [pump-err (doto (Pipe. (.getErrorStream proc)
-                                    (TeeOutputStream. System/err err-output))
-                         .start)]
+        (if passphrase
+          (with-open [in (.getOutputStream proc)]
+            (io/copy passphrase in)))
+        (let [pump-err (doto (Pipe. err
+                                    (TeeOutputStream. System/err
+                                                      err-output))
+                        .start)]
           (.join pump-err)
           (let [exit-code (.waitFor proc)]
             {:exit exit-code
@@ -126,11 +135,26 @@
     (catch java.io.IOException e
       {:exit 1 :out "" :err (.getMessage e)})))
 
+(defn gpg
+  "Shells out to (gpg-program) with the given arguments"
+  [& args]
+  (apply gpg-with-passphrase nil args))
+
 (defn gpg-available?
   "Verifies (gpg-program) exists"
   []
   (zero? (:exit (gpg "--version"))))
 
+(defn gpg-version
+  "parse and return the version of gpg available"
+  []
+  (let [pattern #"gpg\s+\(GnuPG\)\s+(\d+)\.(\d+)\.(\d+)"]
+    (if-let [[_ major minor patch]
+             (re-find pattern (:out (gpg "--version")))]
+      {:major (Integer/parseInt major)
+       :minor (Integer/parseInt minor)
+       :patch (Integer/parseInt patch)})))
+
 (defn credentials-fn
   "Decrypt map from credentials.clj.gpg in Leiningen home if present."
   ([] (let [cred-file (io/file (leiningen-home) "credentials.clj.gpg")]
@@ -156,25 +180,37 @@
                                (re-find re? (:url settings)))]
                 cred))))
 
+(defn resolve-env-keyword
+  "Resolve usage of :env and :env/foo in project.clj"
+  [k v]
+  (cond (= :env v)
+        (getenv (str "LEIN_"
+                     (-> (name k)
+                         (str/upper-case)
+                         (str/replace "-" "_"))))
+
+        (and (keyword? v) (= "env" (namespace v)))
+        (getenv (str/upper-case (name v)))
+
+        :else nil))
+
+(defn- resolve-gpg-keyword
+  "Resolve usage of :gpg in project.clj"
+  [source-settings k v]
+  (cond (= :gpg v)
+        (get (match-credentials source-settings (credentials)) k)))
+
 (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)
-                  (getenv (str "LEIN_" (str/upper-case (name k))))
-
-                  (and (keyword? v) (= "env" (namespace v)))
-                  (getenv (str/upper-case (name v)))
-
-                  (= :gpg v)
-                  (get (match-credentials source-settings (credentials)) k)
-
-                  (coll? v) ;; collection of places to look
+            (or (resolve-env-keyword k v)
+                (resolve-gpg-keyword source-settings k v)
+                (if (coll? v) ;; collection of places to look
                   (->> (map resolve v)
                        (remove nil?)
-                       first)
-
-                  :else v))]
+                       first))
+                v))]
     (if (#{:username :password :passphrase :private-key-file} k)
       (assoc result k (resolve v))
       (assoc result k v))))
diff --git a/src/leiningen/deploy.clj b/src/leiningen/deploy.clj
index 8a6cafff..512fdfc4 100644
--- a/src/leiningen/deploy.clj
+++ b/src/leiningen/deploy.clj
@@ -74,16 +74,37 @@
         (add-auth-interactively))))
 
 (defn signing-args
-  "Produce GPG arguments for signing a file."
+  "Produce GPG arguments for signing a file, taking the version of gpg
+  into account as necessary."
   [file opts]
-  (let [key-spec (if-let [key (:gpg-key opts)]
-                   ["--default-key" key])]
-    `["--yes" "-ab" ~@key-spec "--" ~file]))
+  (let [key-args (concat
+                  (if-let [key (:gpg-key opts)]
+                    ["--default-key" key])
+                  (if (:gpg-passphrase opts)
+                    (let [{:keys [major minor patch]} (user/gpg-version)
+                          version (+ major (/ minor 10.))]
+                      (if (> version 2.0)
+                        ; gpg 2.1 and newer
+                        ["--passphrase-fd" "0"
+                         "--pinentry-mode" "loopback"]
+                        ; gpg 2.0 and older
+                        ["--passphrase-fd" "0" "--batch"]))))]
+    `["--yes" "-ab" ~@key-args "--" ~file]))
+
+(defn signing-passphrase
+  "Produce GPG passphrase if specified in project"
+  [opts]
+  (if-let [pp (:gpg-passphrase opts)]
+    (or (user/resolve-env-keyword :gpg-passphrase pp) 
+        pp)))
 
 (defn sign
   "Create a detached signature and return the signature file name."
   [file opts]
-  (let [{:keys [err exit]} (apply user/gpg (signing-args file opts))]
+  (let [pass (signing-passphrase opts)
+        args (signing-args file opts)
+        _    (main/info "Signing: gpg " args)
+        {:keys [err exit]} (apply user/gpg-with-passphrase (cons pass args))]
     (when-not (zero? exit)
       (main/abort "Could not sign"
                   (str file "\n" err (if err "\n")
diff --git a/test/leiningen/test/deploy.clj b/test/leiningen/test/deploy.clj
index b9fccb56..7af98fb3 100644
--- a/test/leiningen/test/deploy.clj
+++ b/test/leiningen/test/deploy.clj
@@ -2,6 +2,7 @@
   (:use [clojure.test]
         [clojure.java.io :only [file]]
         [leiningen.deploy]
+        [leiningen.core.user :as user]
         [leiningen.test.helper :only [delete-file-recursively
                                       tmp-dir sample-project
                                       sample-deploy-project]]))
@@ -66,7 +67,31 @@
     (is (= (signing-args "foo.jar" nil)
            ["--yes" "-ab" "--" "foo.jar"]))
     (is (= (signing-args "foo.jar" {:gpg-key "123456"})
-           ["--yes" "-ab" "--default-key" "123456" "--" "foo.jar"])))
+           ["--yes" "-ab" "--default-key" "123456" "--" "foo.jar"]))
+    (with-redefs [user/gpg-version (fn [] {:major 2 :minor 1 :patch 0})]
+      (is (= (signing-args "foo.jar" {:gpg-key "123456" :gpg-passphrase "abc"})
+             ["--yes" "-ab" "--default-key" "123456"
+              "--passphrase-fd" "0" "--pinentry-mode" "loopback"
+              "--" "foo.jar"]))
+      (is (= (signing-args "foo.jar" {:gpg-passphrase "abc"})
+             ["--yes" "-ab"
+              "--passphrase-fd" "0" "--pinentry-mode" "loopback"
+              "--" "foo.jar"])))
+    (with-redefs [user/gpg-version (fn [] {:major 1 :minor 4 :patch 0})]
+      (is (= (signing-args "foo.jar" {:gpg-key "123456" :gpg-passphrase "abc"})
+             ["--yes" "-ab" "--default-key" "123456"
+              "--passphrase-fd" "0" "--batch"
+              "--" "foo.jar"]))
+      (is (= (signing-args "foo.jar" {:gpg-passphrase "abc"})
+             ["--yes" "-ab"
+              "--passphrase-fd" "0" "--batch"
+              "--" "foo.jar"])))
+    (is (= (signing-passphrase {}) nil))
+    (is (= (signing-passphrase {:gpg-passphrase "abc"}) "abc"))
+    (with-redefs [user/getenv (fn [v] (if (= v "LEIN_GPG_PASSPHRASE") "abc" nil))]
+      (is (= (signing-passphrase {:gpg-passphrase :env}) "abc")))
+    (with-redefs [user/getenv (fn [v] (if (= v "MYPASS") "abc" nil))]
+      (is (= (signing-passphrase {:gpg-passphrase :env/mypass}) "abc"))))
   (testing "Key selection"
     (is (= (:gpg-key (signing-opts {:signing {:gpg-key "key-project"}}
                                    ["repo" {:signing {:gpg-key "key-repo"}}]))