diff --git a/shlax/targets/buildah.py b/shlax/targets/buildah.py
index 69c68ca..11b74fd 100644
--- a/shlax/targets/buildah.py
+++ b/shlax/targets/buildah.py
@@ -136,7 +136,7 @@ class Buildah(Localhost):
         cli.exit_code = await proc.wait()
 
     async def clean(self, *args, **kwargs):
-        if self.mnt:
+        if self.mnt is not None:
             await self.exec('buildah', 'umount', self.ctr, buildah=False)
-        if self.ctr:
+        if self.ctr is not None:
             await self.exec('buildah', 'rm', self.ctr, buildah=False)
diff --git a/tests/test_proc.py b/tests/test_proc.py
index 7ffe2ba..4276263 100644
--- a/tests/test_proc.py
+++ b/tests/test_proc.py
@@ -29,6 +29,7 @@ test_args_params = [
             ('buildah', 'from', 'alpine'),
             ('buildah', 'mount', ''),
             ('buildah', 'run', '', '--', 'sh', '-euc', 'echo hi'),
+            ('buildah', 'umount', ''),
             ('buildah', 'rm', ''),
         ]
     ),
@@ -38,6 +39,7 @@ test_args_params = [
             ('buildah', 'from', 'alpine'),
             ('buildah', 'mount', ''),
             ('buildah', 'run', '--user', 'root', '', '--', 'sh', '-euc', 'echo hi'),
+            ('buildah', 'umount', ''),
             ('buildah', 'rm', ''),
         ]
     ),
@@ -47,6 +49,7 @@ test_args_params = [
             ('ssh', 'host', 'buildah', 'from', 'alpine'),
             ('ssh', 'host', 'buildah', 'mount', ''),
             ('ssh', 'host', 'buildah', 'run', '--user', 'root', '', '--', 'sh', '-euc', 'echo hi'),
+            ('ssh', 'host', 'buildah', 'umount', ''),
             ('ssh', 'host', 'buildah', 'rm', ''),
         ]
     ),