diff --git a/osbuild/buildroot.py b/osbuild/buildroot.py
index bcce4c69..826509bd 100644
--- a/osbuild/buildroot.py
+++ b/osbuild/buildroot.py
@@ -59,7 +59,7 @@ class BuildRoot(contextlib.AbstractContextManager):
     only when exiting the context manager.
     """
 
-    def __init__(self, root, runner, libdir, path="/run/osbuild", var="/var/tmp"):
+    def __init__(self, root, runner, libdir, var, path="/run/osbuild"):
         self._exitstack = None
         self._rootdir = root
         self._rundir = path
diff --git a/test/mod/test_buildroot.py b/test/mod/test_buildroot.py
index 9558fb2d..1c4bce8d 100644
--- a/test/mod/test_buildroot.py
+++ b/test/mod/test_buildroot.py
@@ -30,7 +30,7 @@ class TestBuildRoot(test.TestBase):
         var.mkdir()
 
         monitor = NullMonitor(sys.stderr.fileno())
-        with BuildRoot("/", runner, libdir, var=var) as root:
+        with BuildRoot("/", runner, libdir, var) as root:
 
             r = root.run(["/usr/bin/true"], monitor)
             self.assertEqual(r.returncode, 0)
@@ -50,7 +50,7 @@ class TestBuildRoot(test.TestBase):
 
         logfile = os.path.join(self.tmp.name, "log.txt")
 
-        with BuildRoot("/", runner, libdir, var=var) as root, \
+        with BuildRoot("/", runner, libdir, var) as root, \
              open(logfile, "w") as log:
 
             monitor = LogMonitor(log.fileno())
@@ -73,7 +73,7 @@ class TestBuildRoot(test.TestBase):
         data = "42. cats are superior to dogs"
 
         monitor = NullMonitor(sys.stderr.fileno())
-        with BuildRoot("/", runner, libdir, var=var) as root:
+        with BuildRoot("/", runner, libdir, var) as root:
 
             r = root.run(["/usr/bin/echo", data], monitor)
             self.assertEqual(r.returncode, 0)
@@ -93,7 +93,7 @@ class TestBuildRoot(test.TestBase):
         scripts = os.path.join(self.locate_test_data(), "scripts")
 
         monitor = NullMonitor(sys.stderr.fileno())
-        with BuildRoot("/", runner, libdir, var=var) as root:
+        with BuildRoot("/", runner, libdir, var) as root:
 
             ro_binds = [f"{scripts}:/scripts"]
 
@@ -127,7 +127,7 @@ class TestBuildRoot(test.TestBase):
         scripts = os.path.join(self.locate_test_data(), "scripts")
 
         monitor = NullMonitor(sys.stderr.fileno())
-        with BuildRoot("/", runner, libdir, var=var) as root:
+        with BuildRoot("/", runner, libdir, var) as root:
 
             ro_binds = [f"{scripts}:/scripts"]