diff --git a/extras/onewire/onewire.c b/extras/onewire/onewire.c
index 5508684..5111271 100644
--- a/extras/onewire/onewire.c
+++ b/extras/onewire/onewire.c
@@ -216,7 +216,7 @@ onewire_addr_t onewire_search_next(onewire_search_t *search, int pin) {
     uint8_t id_bit_number;
     uint8_t last_zero, search_result;
     int rom_byte_number;
-    uint8_t id_bit, cmp_id_bit;
+    int8_t id_bit, cmp_id_bit;
     onewire_addr_t addr;
     unsigned char rom_byte_mask;
     bool search_direction;