diff --git a/libraries/MySensors/core/MyHwSAMD.cpp b/libraries/MySensors/core/MyHwSAMD.cpp
index 1c282b9..c358419 100644
--- a/libraries/MySensors/core/MyHwSAMD.cpp
+++ b/libraries/MySensors/core/MyHwSAMD.cpp
@@ -116,7 +116,7 @@ void hwSleep(unsigned long ms) {
   ms = ms + 1;
 }
 
-bool hwSleep(uint8_t interrupt, uint8_t mode, unsigned long ms) {
+int8_t hwSleep(uint8_t interrupt, uint8_t mode, unsigned long ms) {
   // TODO: Not supported!
   interrupt = interrupt;
   mode = mode;
@@ -124,7 +124,7 @@ bool hwSleep(uint8_t interrupt, uint8_t mode, unsigned long ms) {
 	return false;
 }
 
-uint8_t hwSleep(uint8_t interrupt1, uint8_t mode1, uint8_t interrupt2, uint8_t mode2, unsigned long ms) {
+int8_t hwSleep(uint8_t interrupt1, uint8_t mode1, uint8_t interrupt2, uint8_t mode2, unsigned long ms) {
   // TODO: Not supported!
   interrupt1 = interrupt1;
   mode1 = mode1;