diff --git a/eth_interface.c b/eth_interface.c
index 46078f8..318f10b 100644
--- a/eth_interface.c
+++ b/eth_interface.c
@@ -42,7 +42,7 @@ static void ethintf_register(EthInterface * intf) {
 }
 
 // interface processing thread
-static ETHLIB_OS_THREAD_FUNCTION(task_ethintf);
+static ThreadReturnType task_ethintf (ThreadParamType param);
 
 EthInterface *ethintf_new(EthIODef * io) {
     EthInterface * ethIntf = (EthInterface *)dynmem_alloc(sizeof(EthInterface));
@@ -75,7 +75,7 @@ EthInterface *ethintf_new(EthIODef * io) {
     return ethIntf;
 }
 
-static ETHLIB_OS_THREAD_FUNCTION(task_ethintf) {
+static ThreadReturnType task_ethintf (ThreadParamType param) {
     EthInterface * intf = (EthInterface *) param;
     while (true) {
         ETHLIB_OS_SEM_WAIT(&intf->rxSem);