diff --git a/MAINTAINERS b/MAINTAINERS
index 0c766961f3..667acd933c 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -4397,6 +4397,7 @@ M: Thomas Huth <thuth@redhat.com>
 R: Philippe Mathieu-Daudé <philmd@linaro.org>
 R: Daniel P. Berrange <berrange@redhat.com>
 F: docs/devel/testing/functional.rst
+F: scripts/clean_functional_cache.py
 F: tests/functional/qemu_test/
 
 Windows Hosted Continuous Integration
diff --git a/scripts/clean_functional_cache.py b/scripts/clean_functional_cache.py
new file mode 100755
index 0000000000..c3370ffbb8
--- /dev/null
+++ b/scripts/clean_functional_cache.py
@@ -0,0 +1,45 @@
+#!/usr/bin/env python3
+#
+# SPDX-License-Identifier: GPL-2.0-or-later
+#
+"""Delete stale assets from the download cache of the functional tests"""
+
+import os
+import stat
+import sys
+import time
+from pathlib import Path
+
+
+cache_dir_env = os.getenv('QEMU_TEST_CACHE_DIR')
+if cache_dir_env:
+    cache_dir = Path(cache_dir_env, "download")
+else:
+    cache_dir = Path(Path("~").expanduser(), ".cache", "qemu", "download")
+
+if not cache_dir.exists():
+    print(f"Cache dir {cache_dir} does not exist!", file=sys.stderr)
+    sys.exit(1)
+
+os.chdir(cache_dir)
+
+for file in cache_dir.iterdir():
+    # Only consider the files that use a sha256 as filename:
+    if len(file.name) != 64:
+        continue
+
+    try:
+        timestamp = int(file.with_suffix(".stamp").read_text())
+    except FileNotFoundError:
+        # Assume it's an old file that was already in the cache before we
+        # added the code for evicting stale assets. Use the release date
+        # of QEMU v10.1 as a default timestamp.
+        timestamp = time.mktime((2025, 8, 26, 0, 0, 0, 0, 0, 0))
+
+    age = time.time() - timestamp
+
+    # Delete files older than half of a year (183 days * 24h * 60m * 60s)
+    if age > 15811200:
+        print(f"Removing {cache_dir}/{file.name}.")
+        file.chmod(stat.S_IWRITE)
+        file.unlink()
diff --git a/tests/Makefile.include b/tests/Makefile.include
index e47ef4d45c..d4dfbf3716 100644
--- a/tests/Makefile.include
+++ b/tests/Makefile.include
@@ -111,6 +111,7 @@ $(FUNCTIONAL_TARGETS): check-venv
 .PHONY: check-functional
 check-functional: check-venv
 	@$(NINJA) precache-functional
+	@$(PYTHON) $(SRC_PATH)/scripts/clean_functional_cache.py
 	@QEMU_TEST_NO_DOWNLOAD=1 $(MAKE) SPEED=thorough check-func check-func-quick
 
 .PHONY: check-func check-func-quick