diff --git a/src/stratifier.c b/src/stratifier.c
index 4d3cf5f3..87dcc1b7 100644
--- a/src/stratifier.c
+++ b/src/stratifier.c
@@ -2583,7 +2583,10 @@ static void suggest_diff(stratum_instance_t *client, const char *method, json_t
 	client->suggest_diff = sdiff;
 	if (client->diff == sdiff)
 		return;
-	client->diff = sdiff;
+	if (sdiff < client->ckp->mindiff)
+		client->diff = client->ckp->mindiff;
+	else
+		client->diff = sdiff;
 	stratum_send_diff(client);
 }