diff --git a/builtin/index-pack.c b/builtin/index-pack.c
index 0d03cb442d..4b8d86e0ad 100644
--- a/builtin/index-pack.c
+++ b/builtin/index-pack.c
@@ -1597,7 +1597,7 @@ static void read_v2_anomalous_offsets(struct packed_git *p,
 
 	/* The address of the 4-byte offset table */
 	idx1 = (((const uint32_t *)((const uint8_t *)p->index_data + p->crc_offset))
-		+ p->num_objects /* CRC32 table */
+		+ (size_t)p->num_objects /* CRC32 table */
 		);
 
 	/* The address of the 8-byte offset table */
diff --git a/pack-check.c b/pack-check.c
index dad6d8ae7f..db3adf8781 100644
--- a/pack-check.c
+++ b/pack-check.c
@@ -39,7 +39,7 @@ int check_pack_crc(struct packed_git *p, struct pack_window **w_curs,
 	} while (len);
 
 	index_crc = p->index_data;
-	index_crc += 2 + 256 + p->num_objects * (the_hash_algo->rawsz/4) + nr;
+	index_crc += 2 + 256 + (size_t)p->num_objects * (the_hash_algo->rawsz/4) + nr;
 
 	return data_crc != ntohl(*index_crc);
 }
diff --git a/pack-revindex.c b/pack-revindex.c
index d28a7e43d0..ecdde39cf4 100644
--- a/pack-revindex.c
+++ b/pack-revindex.c
@@ -130,7 +130,7 @@ static void create_pack_revindex(struct packed_git *p)
 
 	if (p->index_version > 1) {
 		const uint32_t *off_32 =
-			(uint32_t *)(index + 8 + p->num_objects * (hashsz + 4));
+			(uint32_t *)(index + 8 + (size_t)p->num_objects * (hashsz + 4));
 		const uint32_t *off_64 = off_32 + p->num_objects;
 		for (i = 0; i < num_ent; i++) {
 			const uint32_t off = ntohl(*off_32++);
diff --git a/packfile.c b/packfile.c
index 0929ebe4fc..a72c2a261f 100644
--- a/packfile.c
+++ b/packfile.c
@@ -148,7 +148,7 @@ int load_idx(const char *path, const unsigned int hashsz, void *idx_map,
 		 *  - hash of the packfile
 		 *  - file checksum
 		 */
-		if (idx_size != 4 * 256 + nr * (hashsz + 4) + hashsz + hashsz)
+		if (idx_size != 4 * 256 + (size_t)nr * (hashsz + 4) + hashsz + hashsz)
 			return error("wrong index v1 file size in %s", path);
 	} else if (version == 2) {
 		/*
@@ -164,10 +164,10 @@ int load_idx(const char *path, const unsigned int hashsz, void *idx_map,
 		 * variable sized table containing 8-byte entries
 		 * for offsets larger than 2^31.
 		 */
-		unsigned long min_size = 8 + 4*256 + nr*(hashsz + 4 + 4) + hashsz + hashsz;
+		unsigned long min_size = 8 + 4*256 + (size_t)nr*(hashsz + 4 + 4) + hashsz + hashsz;
 		unsigned long max_size = min_size;
 		if (nr)
-			max_size += (nr - 1)*8;
+			max_size += ((size_t)nr - 1)*8;
 		if (idx_size < min_size || idx_size > max_size)
 			return error("wrong index v2 file size in %s", path);
 		if (idx_size != min_size &&
@@ -1933,14 +1933,14 @@ off_t nth_packed_object_offset(const struct packed_git *p, uint32_t n)
 	const unsigned int hashsz = the_hash_algo->rawsz;
 	index += 4 * 256;
 	if (p->index_version == 1) {
-		return ntohl(*((uint32_t *)(index + (hashsz + 4) * n)));
+		return ntohl(*((uint32_t *)(index + (hashsz + 4) * (size_t)n)));
 	} else {
 		uint32_t off;
-		index += 8 + p->num_objects * (hashsz + 4);
+		index += 8 + (size_t)p->num_objects * (hashsz + 4);
 		off = ntohl(*((uint32_t *)(index + 4 * n)));
 		if (!(off & 0x80000000))
 			return off;
-		index += p->num_objects * 4 + (off & 0x7fffffff) * 8;
+		index += (size_t)p->num_objects * 4 + (off & 0x7fffffff) * 8;
 		check_pack_index_ptr(p, index);
 		return get_be64(index);
 	}