diff --git a/apt_info.py b/apt_info.py
index ee4975c..21d7416 100755
--- a/apt_info.py
+++ b/apt_info.py
@@ -75,7 +75,7 @@ def _write_autoremove_pending(registry, cache):
 
 
 def _write_cache_timestamps(registry):
-    g = Gauge('apt_update_timestamp_seconds', "Apt update last run time.", registry=registry)
+    g = Gauge('apt_package_cache_timestamp_seconds', "Apt update last run time.", registry=registry)
     try:
         g.set(os.stat('/var/cache/apt/pkgcache.bin').st_mtime)
     except OSError: