diff --git a/osbuild/util/fscache.py b/osbuild/util/fscache.py
index 4576f8d4..e99ae87d 100644
--- a/osbuild/util/fscache.py
+++ b/osbuild/util/fscache.py
@@ -204,6 +204,7 @@ class FsCache(contextlib.AbstractContextManager, os.PathLike):
     _filename_cache_info = "cache.info"
     _filename_cache_lock = "cache.lock"
     _filename_cache_size = "cache.size"
+    _filename_cache_tag = "CACHEDIR.TAG"
     _filename_object_info = "object.info"
     _filename_object_lock = "object.lock"
     _version_current = 1
@@ -615,6 +616,11 @@ class FsCache(contextlib.AbstractContextManager, os.PathLike):
 
         # Create the file-scaffolding of the cache. We fill in the default
         # information and ignore racing operations.
+        with self._atomic_file(self._filename_cache_tag, self._dirname_objects, ignore_exist=True) as f:
+            f.write(
+                "Signature: 8a477f597d28d172789f06886806bc55\n"
+                "# This is a cache directory tag created by osbuild (see https://bford.info/cachedir/)\n"
+            )
         with self._atomic_file(self._filename_cache_info, self._dirname_objects, ignore_exist=True) as f:
             json.dump({"version": self._version_current}, f)
         with self._atomic_file(self._filename_cache_lock, self._dirname_objects, ignore_exist=True) as f:
diff --git a/test/mod/test_util_fscache.py b/test/mod/test_util_fscache.py
index 9361bfcc..b81b00d5 100644
--- a/test/mod/test_util_fscache.py
+++ b/test/mod/test_util_fscache.py
@@ -190,10 +190,12 @@ def test_scaffolding(tmpdir):
     with cache:
         pass
 
-    assert len(list(os.scandir(tmpdir))) == 5
+    assert len(list(os.scandir(tmpdir))) == 6
     assert len(list(os.scandir(os.path.join(tmpdir, cache._dirname_objects)))) == 0
     assert len(list(os.scandir(os.path.join(tmpdir, cache._dirname_stage)))) == 0
 
+    with open(os.path.join(tmpdir, cache._filename_cache_tag), "r", encoding="utf8") as f:
+        assert len(f.read()) > 0
     with open(os.path.join(tmpdir, cache._filename_cache_info), "r", encoding="utf8") as f:
         assert json.load(f) == {"version": 1}
     with open(os.path.join(tmpdir, cache._filename_cache_lock), "r", encoding="utf8") as f:
@@ -202,6 +204,20 @@ def test_scaffolding(tmpdir):
         assert f.read() == "0"
 
 
+def test_cachedir_tag(tmpdir):
+    #
+    # Verify compatibility to the cachedir-tag specification.
+    #
+
+    cache = fscache.FsCache("osbuild-test-appid", tmpdir)
+
+    with cache:
+        pass
+
+    with open(os.path.join(tmpdir, "CACHEDIR.TAG"), "r", encoding="utf8") as f:
+        assert f.read(43) == "Signature: 8a477f597d28d172789f06886806bc55"
+
+
 def test_cache_info(tmpdir):
     #
     # Verify that the cache reads and augments cache information. Also verify