diff --git a/engine.c b/engine.c
index 89217a9..f656146 100644
--- a/engine.c
+++ b/engine.c
@@ -654,7 +654,7 @@ ptrack_mark_block(RelFileNodeBackend smgr_rnode,
 				  ForkNumber forknum, BlockNumber blocknum)
 {
 	PtBlockId	bid;
-	size_t		hash;
+	uint64		hash;
 	size_t		slot1;
 	size_t		slot2;
 	XLogRecPtr	new_lsn;
@@ -676,8 +676,8 @@ ptrack_mark_block(RelFileNodeBackend smgr_rnode,
 	bid.blocknum = blocknum;
 
 	hash = BID_HASH_FUNC(bid);
-	slot1 = hash % PtrackContentNblocks;
-	slot2 = ((hash << 32) | (hash >> 32)) % PtrackContentNblocks;
+	slot1 = (size_t)(hash % PtrackContentNblocks);
+	slot2 = (size_t)(((hash << 32) | (hash >> 32)) % PtrackContentNblocks);
 
 	if (RecoveryInProgress())
 		new_lsn = GetXLogReplayRecPtr(NULL);
diff --git a/engine.h b/engine.h
index e46f803..3386cc2 100644
--- a/engine.h
+++ b/engine.h
@@ -86,7 +86,7 @@ typedef PtrackMapHdr * PtrackMap;
 /* Block address 'bid' to hash.  To get slot position in map should be divided
  * with '% PtrackContentNblocks' */
 #define BID_HASH_FUNC(bid) \
-		(size_t)(DatumGetUInt64(hash_any_extended((unsigned char *)&bid, sizeof(bid), 0)))
+		(DatumGetUInt64(hash_any_extended((unsigned char *)&bid, sizeof(bid), 0)))
 
 /*
  * Per process pointer to shared ptrack_map
diff --git a/ptrack.c b/ptrack.c
index 40630e7..66f5676 100644
--- a/ptrack.c
+++ b/ptrack.c
@@ -487,7 +487,7 @@ ptrack_get_pagemapset(PG_FUNCTION_ARGS)
 
 	while (true)
 	{
-		size_t		hash;
+		uint64		hash;
 		size_t		slot1;
 		size_t		slot2;
 		XLogRecPtr	update_lsn1;
@@ -535,7 +535,7 @@ ptrack_get_pagemapset(PG_FUNCTION_ARGS)
 		}
 
 		hash = BID_HASH_FUNC(ctx->bid);
-		slot1 = hash % PtrackContentNblocks;
+		slot1 = (size_t)(hash % PtrackContentNblocks);
 
 		update_lsn1 = pg_atomic_read_u64(&ptrack_map->entries[slot1]);
 
@@ -547,7 +547,7 @@ ptrack_get_pagemapset(PG_FUNCTION_ARGS)
 		/* Only probe the second slot if the first one is marked */
 		if (update_lsn1 >= ctx->lsn)
 		{
-			slot2 = ((hash << 32) | (hash >> 32)) % PtrackContentNblocks;
+			slot2 = (size_t)(((hash << 32) | (hash >> 32)) % PtrackContentNblocks);
 			update_lsn2 = pg_atomic_read_u64(&ptrack_map->entries[slot2]);
 
 			if (update_lsn2 != InvalidXLogRecPtr)