diff --git a/OneWire.cpp b/OneWire.cpp
index 38bf4ee..2cf8a79 100644
--- a/OneWire.cpp
+++ b/OneWire.cpp
@@ -164,7 +164,7 @@ void OneWire::begin(uint8_t pin)
 uint8_t OneWire::reset(void)
 {
 	IO_REG_TYPE mask IO_REG_MASK_ATTR = bitmask;
-	volatile IO_REG_TYPE *reg IO_REG_BASE_ATTR = baseReg;
+	__attribute__((unused)) volatile IO_REG_TYPE *reg IO_REG_BASE_ATTR = baseReg;
 	uint8_t r;
 	uint8_t retries = 125;
 
@@ -198,7 +198,7 @@ uint8_t OneWire::reset(void)
 void OneWire::write_bit(uint8_t v)
 {
 	IO_REG_TYPE mask IO_REG_MASK_ATTR = bitmask;
-	volatile IO_REG_TYPE *reg IO_REG_BASE_ATTR = baseReg;
+	__attribute__((unused)) volatile IO_REG_TYPE *reg IO_REG_BASE_ATTR = baseReg;
 
 	if (v & 1) {
 		noInterrupts();
@@ -226,7 +226,7 @@ void OneWire::write_bit(uint8_t v)
 uint8_t OneWire::read_bit(void)
 {
 	IO_REG_TYPE mask IO_REG_MASK_ATTR = bitmask;
-	volatile IO_REG_TYPE *reg IO_REG_BASE_ATTR = baseReg;
+	__attribute__((unused)) volatile IO_REG_TYPE *reg IO_REG_BASE_ATTR = baseReg;
 	uint8_t r;
 
 	noInterrupts();