diff --git a/lib/git.js b/lib/git.js
index 0b3bc22..9eda87f 100644
--- a/lib/git.js
+++ b/lib/git.js
@@ -81,7 +81,10 @@ function replaceTree(targetDir, ourDir, commitMessage) {
 }
 
 function push(targetDir, repo, branch) {
-  return run("git", ["push", repo, branch], { cwd: targetDir });
+  return run("git", ["pull", "--rebase", repo, branch], { cwd: targetDir })
+    .then(function () {
+      return run("git", ["push", repo, branch], { cwd: targetDir });
+    });
 }
 
 function origin(targetDir) {