diff --git a/revision.c b/revision.c
index 7ff61ff..8a8c178 100644
--- a/revision.c
+++ b/revision.c
@@ -884,7 +884,7 @@ static void cherry_pick_list(struct commit_list *list, struct rev_info *revs)
 /* How many extra uninteresting commits we want to see.. */
 #define SLOP 5
 
-static int still_interesting(struct commit_list *src, unsigned long date, int slop,
+static int still_interesting(struct commit_list *src, timestamp_t date, int slop,
 			     struct commit **interesting_cache)
 {
 	/*
@@ -1018,7 +1018,7 @@ static void limit_left_right(struct commit_list *list, struct rev_info *revs)
 static int limit_list(struct rev_info *revs)
 {
 	int slop = SLOP;
-	unsigned long date = ~0ul;
+	timestamp_t date = TIME_MAX;
 	struct commit_list *list = revs->commits;
 	struct commit_list *newlist = NULL;
 	struct commit_list **p = &newlist;
@@ -1215,7 +1215,7 @@ static void handle_one_reflog_commit(struct object_id *oid, void *cb_data)
 }
 
 static int handle_one_reflog_ent(struct object_id *ooid, struct object_id *noid,
-		const char *email, unsigned long timestamp, int tz,
+		const char *email, timestamp_t timestamp, int tz,
 		const char *message, void *cb_data)
 {
 	handle_one_reflog_commit(ooid, cb_data);