diff --git a/tests/model/test_ocrd_mets.py b/tests/model/test_ocrd_mets.py
index 5062fe2270..739db7625a 100644
--- a/tests/model/test_ocrd_mets.py
+++ b/tests/model/test_ocrd_mets.py
@@ -395,8 +395,9 @@ def temp_env_var(k, v):
         environ.pop(k, None)
 
 def test_envvar():
-    assert OcrdMets(filename=assets.url_of('SBB0000F29300010000/data/mets.xml'), cache_flag=True)._cache_flag
-    assert not OcrdMets(filename=assets.url_of('SBB0000F29300010000/data/mets.xml'), cache_flag=False)._cache_flag
+    with temp_env_var('OCRD_METS_CACHING', None):
+        assert OcrdMets(filename=assets.url_of('SBB0000F29300010000/data/mets.xml'), cache_flag=True)._cache_flag
+        assert not OcrdMets(filename=assets.url_of('SBB0000F29300010000/data/mets.xml'), cache_flag=False)._cache_flag
     with temp_env_var('OCRD_METS_CACHING', 'true'):
         assert OcrdMets(filename=assets.url_of('SBB0000F29300010000/data/mets.xml'), cache_flag=True)._cache_flag
         assert OcrdMets(filename=assets.url_of('SBB0000F29300010000/data/mets.xml'), cache_flag=False)._cache_flag