diff --git a/mu b/mu
index 6e0ecd4..dd45c5e 100755
--- a/mu
+++ b/mu
@@ -1,4 +1,8 @@
 #!/usr/bin/env python
 if __name__ == '__main__':
+    import sys
     import mu_repo
-    mu_repo.main()
+
+    status = mu_repo.main()
+    success = status is None or status.succeeded
+    sys.exit(0 if success else 1)
diff --git a/mu.py b/mu.py
index 16fd582..5ac4715 100644
--- a/mu.py
+++ b/mu.py
@@ -1,4 +1,8 @@
 #!/usr/bin/env python
 if __name__ == '__main__':
+    import sys
     import mu_repo
-    mu_repo.main()
+
+    status = mu_repo.main()
+    success = status is None or status.succeeded
+    sys.exit(0 if success else 1)
diff --git a/mu_repo/__init__.py b/mu_repo/__init__.py
index 38f35ef..e45d244 100644
--- a/mu_repo/__init__.py
+++ b/mu_repo/__init__.py
@@ -26,6 +26,16 @@ def __init__(self, status_message, succeeded, config=None):
         self.succeeded = succeeded
         self.config = config
 
+    def __repr__(self):
+        return f"Status(status_message={self.status_message!r}, succeeded={self.succeeded!r})"
+
+    def __eq__(self, other):
+        return (
+            self.status_message == other.status_message
+            and self.succeeded == other.succeeded
+            and self.config == other.config
+        )
+
 #===================================================================================================
 # Params
 #===================================================================================================
diff --git a/mu_repo/action_checkout.py b/mu_repo/action_checkout.py
index dcc1723..980654b 100644
--- a/mu_repo/action_checkout.py
+++ b/mu_repo/action_checkout.py
@@ -2,6 +2,7 @@
 from mu_repo.backwards import iteritems
 from mu_repo.get_repos_and_local_branches import GetReposAndLocalBranches
 from mu_repo.print_ import Print
+from mu_repo import Status
 
 #===================================================================================================
 # Run
@@ -33,4 +34,5 @@ def Run(params):
     Print('Found more than one branch that matches ${START_COLOR}%s${RESET_COLOR}:\n' % params.args[1])
     PrintBranchToRepos(branch_to_repos, params)
     Print('\n${START_COLOR}ERROR${RESET_COLOR}: unable to decide branch to work on.', __color__='RED')
+    return Status("ERROR", succeeded=False)
 
diff --git a/mu_repo/action_default.py b/mu_repo/action_default.py
index 9f425ec..b020a07 100644
--- a/mu_repo/action_default.py
+++ b/mu_repo/action_default.py
@@ -49,7 +49,12 @@ def Run(params, on_output=None):
         else:
             commands.append(ParallelCmd(repo, [config.git] + args))
 
-    ExecuteInParallel(commands, on_output, serial=config.serial)
-
-    return Status('Finished', True)
+    cmd_return_codes = ExecuteInParallel(commands, on_output, serial=config.serial)
+    failed_cmds = [cmd for (cmd, returncode) in cmd_return_codes if returncode != 0]
+    if failed_cmds:
+        message = "Failed:\n" + "\n".join(f'  {x.repo}' for x in failed_cmds)
+        Print('\n${START_COLOR}' + message + '${RESET_COLOR}', __color__="RED")
+        return Status(message, False)
+    else:
+        return Status('Finished', True)
 
diff --git a/mu_repo/execute_git_command_in_thread.py b/mu_repo/execute_git_command_in_thread.py
index 9dee8e9..b7c952a 100644
--- a/mu_repo/execute_git_command_in_thread.py
+++ b/mu_repo/execute_git_command_in_thread.py
@@ -42,6 +42,7 @@ def __init__(self, repo, cmd, output_queue):
         self.repo = repo
         self.cmd = cmd
         self.output_queue = output_queue
+        self.returncode = None
 
 
     class ReaderThread(threading.Thread):
@@ -97,6 +98,7 @@ def run(self, serial=False):
                 PrintError('Error executing: ' + ' '.join(cmd) + ' on: ' + repo)
             if p is not None:
                 p.wait()
+            self.returncode = p.returncode
 
         else:
             try:
@@ -123,6 +125,7 @@ def run(self, serial=False):
             stderr = AsStr(self.stderr_thread.GetFullOutput())
 
             self._HandleOutput(msg, stdout, stderr)
+            self.returncode = p.returncode
 
     def GetPartialStderrOutput(self):
         stderr_thread = getattr(self, 'stderr_thread', None)
diff --git a/mu_repo/execute_parallel_command.py b/mu_repo/execute_parallel_command.py
index a203bc6..58b5bab 100644
--- a/mu_repo/execute_parallel_command.py
+++ b/mu_repo/execute_parallel_command.py
@@ -82,6 +82,7 @@ def ExecuteInParallel(commands, on_output=None, serial=False):
     else:
         from mu_repo.execute_git_command_in_thread import ExecuteThreadsHandlingOutputQueue
         ExecuteThreadsHandlingOutputQueue(threads, output_queue, on_output=on_output)
+    return [(commands[i], t.returncode) for i, t in enumerate(threads)]
 
 
 
diff --git a/mu_repo/tests/test_action_default.py b/mu_repo/tests/test_action_default.py
new file mode 100644
index 0000000..f62b007
--- /dev/null
+++ b/mu_repo/tests/test_action_default.py
@@ -0,0 +1,26 @@
+import subprocess
+from pathlib import Path
+
+
+import mu_repo
+
+
+def test_action_default(workdir, monkeypatch):
+    workdir = Path(workdir)
+    monkeypatch.chdir(workdir)
+    subprocess.check_call(f'git init core')
+    subprocess.check_call(f'git init app')
+    (workdir/ 'app/.mu_repo').write_text("repo=.\nrepo=../core\n", encoding="utf-8")
+
+    monkeypatch.chdir(workdir/ 'app')
+    subprocess.check_call(f'git config --add foo.bar foo-value')
+
+    subprocess.check_call(f'git config --get foo.bar')
+
+    status = mu_repo.main(args=['config', '--get', 'core.bare'], config_file='.mu_repo')
+    assert status == mu_repo.Status("Finished", succeeded=True)
+
+    status = mu_repo.main(args=['config', '--get', 'foo.bar'], config_file='.mu_repo')
+    assert status == mu_repo.Status("Failed:\n  ../core", succeeded=False)
+
+
diff --git a/mu_repo/tests/test_checkout.py b/mu_repo/tests/test_checkout.py
index 616ceb5..e79bb76 100644
--- a/mu_repo/tests/test_checkout.py
+++ b/mu_repo/tests/test_checkout.py
@@ -36,17 +36,21 @@ def test_checkout_partial_names(workdir):
     mu_repo.main(config_file='.mu_repo', args=['branch', 'rb-scissors'])
 
     # Checkout fb-rock on both projects
-    mu_repo.main(config_file='.mu_repo', args=['checkout', 'fb-rock'])
+    status = mu_repo.main(config_file='.mu_repo', args=['checkout', 'fb-rock'])
+    assert status == mu_repo.Status("Finished", True)
     assert 'fb-rock' == get_current_branch('app')
     assert 'fb-rock' == get_current_branch('lib')
 
     # Only one possible mathc, switch to rb-scissors
-    mu_repo.main(config_file='.mu_repo', args=['checkout', 'rb-'])
+    status = mu_repo.main(config_file='.mu_repo', args=['checkout', 'rb-'])
+    assert status == mu_repo.Status("Finished", True)
     assert 'rb-scissors' == get_current_branch('app')
     assert 'rb-scissors' == get_current_branch('lib')
 
     # Couldn't guess branch name, do not checkout
-    mu_repo.main(config_file='.mu_repo', args=['checkout', 'fb-'])
+    status = mu_repo.main(config_file='.mu_repo', args=['checkout', 'fb-'])
+    assert status == mu_repo.Status("ERROR", False)
+    assert 'rb-scissors' == get_current_branch('app')
     assert 'rb-scissors' == get_current_branch('lib')