diff --git a/sheetsync/setup.py b/sheetsync/setup.py
index 32933cc..5627eb7 100644
--- a/sheetsync/setup.py
+++ b/sheetsync/setup.py
@@ -7,7 +7,7 @@ setup(
 	install_requires = [
 		"argh",
 		"gevent",
-		"prometheus-client",
+		"prometheus-client==0.7.1", # locked version as we rely on internals
 		"psycogreen",
 		"psycopg2",
 		"python-dateutil",
diff --git a/sheetsync/sheetsync/main.py b/sheetsync/sheetsync/main.py
index 0466ac1..a85595c 100644
--- a/sheetsync/sheetsync/main.py
+++ b/sheetsync/sheetsync/main.py
@@ -201,6 +201,9 @@ class SheetSync(object):
 		for row in result.fetchall():
 			by_id[row.id] = row
 			counts[row.sheet_name, row.category, str(row.poster_moment), row.state, str(bool(row.error))] += 1
+		# Reach into metric internals and forget about all previous values,
+		# or else any values we don't update will remain as a stale count.
+		event_counts._metrics.clear()
 		for labels, count in counts.items():
 			event_counts.labels(*labels).set(count)
 		return by_id