diff --git a/src/signal_handler.cc b/src/signal_handler.cc
index 85be25e5..f16ac1df 100644
--- a/src/signal_handler.cc
+++ b/src/signal_handler.cc
@@ -80,7 +80,7 @@ SignalHandler::set_sigaction_handler(unsigned int signum, handler_slot slot) {
 
   struct sigaction sa;
   sa.sa_sigaction = slot;
-  sa.sa_mask = 0;
+  sa.sa_mask = (sigset_t)0;
   sa.sa_flags = SA_SIGINFO;
 
   if (sigaction(signum, &sa, NULL) == -1)