diff --git a/tests/unit/meson.build b/tests/unit/meson.build
index 0d3f00ba5..c3eefeede 100644
--- a/tests/unit/meson.build
+++ b/tests/unit/meson.build
@@ -241,6 +241,10 @@ test(
     # No special meaning here, it's just a file laying around that is unlikely to go anywhere
     # any time soon.
     '_NIX_TEST_UNIT_DATA': meson.project_source_root() / 'src/nix-env/buildenv.nix',
+    # Use a temporary home directory for the unit tests.
+    # Otherwise, /homeless-shelter is created in the single-user sandbox, and functional tests will fail.
+    # TODO(alois31): handle TMPDIR properly (meson can't, and setting HOME in the test is too late)…
+    'HOME': '/tmp/nix-test/libcmd-unit-tests',
   },
   suite : 'check',
   protocol : 'gtest',