diff --git a/lib/mix/lib/mix/scm/git.ex b/lib/mix/lib/mix/scm/git.ex
index 9bd8ca0eae8..75ae91ecf66 100644
--- a/lib/mix/lib/mix/scm/git.ex
+++ b/lib/mix/lib/mix/scm/git.ex
@@ -29,10 +29,12 @@ defmodule Mix.SCM.Git do
     case opts[:lock] do
       { :git, lock_repo, lock_rev, lock_opts } ->
         File.cd!(opts[:dest], fn ->
+          rev_info = get_rev_info
           cond do
-            lock_repo != opts[:git] -> :outdated
+            lock_repo != opts[:git]          -> :outdated
             lock_opts != get_lock_opts(opts) -> :outdated
-            lock_rev  != get_rev -> :mismatch
+            lock_rev  != rev_info[:rev]      -> :mismatch
+            lock_repo != rev_info[:origin]   -> :outdated
             true -> :ok
           end
         end)
@@ -58,6 +60,10 @@ defmodule Mix.SCM.Git do
 
   def update(opts) do
     File.cd! opts[:dest], fn ->
+      # Ensures origin is set the lock repo
+      location = location(opts[:git])
+      update_origin(location)
+
       command = "git fetch --force --progress"
       if opts[:tag] do
         command = command <> " --tags"
@@ -92,7 +98,12 @@ defmodule Mix.SCM.Git do
   end
 
   defp get_lock(opts, fresh) do
-    lock = if fresh, do: get_rev, else: get_lock_rev(opts[:lock])
+    lock = if fresh do
+             rev_info = get_rev_info
+             rev_info[:rev]
+           else
+             get_lock_rev(opts[:lock])
+           end
     { :git, opts[:git], lock, get_lock_opts(opts) }
   end
 
@@ -117,23 +128,15 @@ defmodule Mix.SCM.Git do
     end
   end
 
-  defp get_rev do
-    check_rev System.cmd('git rev-parse --verify --quiet HEAD')
-  end
-
-  defp check_rev([]),   do: nil
-  defp check_rev(list), do: check_rev(list, [])
-
-  defp check_rev([h|t], acc) when h in ?a..?f or h in ?0..?9 do
-    check_rev(t, [h|acc])
-  end
-
-  defp check_rev(fin, acc) when fin == [?\n] or fin == [] do
-    Enum.reverse(acc) |> iolist_to_binary
+  defp get_rev_info do
+    [origin, rev] = System.cmd('git config remote.origin.url && git rev-parse --verify --quiet HEAD')
+                    |> iolist_to_binary
+                    |> String.split("\n", trim: true)
+    [ origin: origin, rev: rev ]
   end
 
-  defp check_rev(_, _) do
-    nil
+  defp update_origin(location) do
+    System.cmd('git config remote.origin.url #{location}')
   end
 
   defp run_cmd_or_raise(command) do