diff --git a/hex.c b/hex.c
index ab2610e498..845b01a874 100644
--- a/hex.c
+++ b/hex.c
@@ -78,7 +78,8 @@ char *sha1_to_hex(const unsigned char *sha1)
 {
 	static int bufno;
 	static char hexbuffer[4][GIT_SHA1_HEXSZ + 1];
-	return sha1_to_hex_r(hexbuffer[3 & ++bufno], sha1);
+	bufno = (bufno + 1) % ARRAY_SIZE(hexbuffer);
+	return sha1_to_hex_r(hexbuffer[bufno], sha1);
 }
 
 char *oid_to_hex(const struct object_id *oid)
diff --git a/path.c b/path.c
index a8e72955f6..52d889c88e 100644
--- a/path.c
+++ b/path.c
@@ -25,7 +25,8 @@ static struct strbuf *get_pathname(void)
 		STRBUF_INIT, STRBUF_INIT, STRBUF_INIT, STRBUF_INIT
 	};
 	static int index;
-	struct strbuf *sb = &pathname_array[3 & ++index];
+	struct strbuf *sb = &pathname_array[index];
+	index = (index + 1) % ARRAY_SIZE(pathname_array);
 	strbuf_reset(sb);
 	return sb;
 }