diff --git a/modules/zim/lib.py b/modules/zim/lib.py
index 09e518b6..722d1962 100644
--- a/modules/zim/lib.py
+++ b/modules/zim/lib.py
@@ -434,7 +434,7 @@ def find_outdated_zim_files(path: pathlib.Path = None) -> Tuple[List[pathlib.Pat
         return list(), list()
 
     # Find all non-empty Zim files.
-    files = [i for i in walk(path) if i.is_file() and i.stat().st_size and i.suffix == '.zim']
+    files = [i for i in walk(path) if i.is_file() and i.suffix == '.zim' and i.stat().st_size]
     zims = list()
     for file in files:
         try:
diff --git a/wrolpi/common.py b/wrolpi/common.py
index beee0a52..c24f5946 100644
--- a/wrolpi/common.py
+++ b/wrolpi/common.py
@@ -566,6 +566,8 @@ def get_media_directory() -> Path:
         raise ValueError('No test media directory set during testing!!')
 
     if isinstance(TEST_MEDIA_DIRECTORY, pathlib.Path):
+        if not str(TEST_MEDIA_DIRECTORY).startswith('/tmp'):
+            raise RuntimeError('Refusing to run test outside tmp directory!')
         return TEST_MEDIA_DIRECTORY
 
     return MEDIA_DIRECTORY