diff --git a/src/socketcand.c b/src/socketcand.c
index bfd67ba..31be3e8 100644
--- a/src/socketcand.c
+++ b/src/socketcand.c
@@ -42,8 +42,8 @@
 #include "beacon.h"
 
 void print_usage(void);
-void sigint();
-void childdied();
+void sigint(int signum);
+void childdied(int signum);
 void determine_adress();
 int receive_command(int socket, char *buf);
 
@@ -662,12 +662,12 @@ void print_usage(void)
 	printf("\t-h (prints this message)\n");
 }
 
-void childdied()
+void childdied(int signum)
 {
 	wait(NULL);
 }
 
-void sigint()
+void sigint(int signum)
 {
 	if (verbose_flag)
 		PRINT_ERROR("received SIGINT\n");
diff --git a/src/socketcand.h b/src/socketcand.h
index e094d1f..f80739e 100644
--- a/src/socketcand.h
+++ b/src/socketcand.h
@@ -52,7 +52,7 @@ void state_bcm();
 void state_raw();
 void state_isotp();
 void state_control();
-void tcp_quickack();
+void tcp_quickack(int s);
 void state_nobus();
 
 extern int client_socket;
diff --git a/src/socketcandcl.c b/src/socketcandcl.c
index 50716eb..3913c76 100644
--- a/src/socketcandcl.c
+++ b/src/socketcandcl.c
@@ -56,7 +56,7 @@
 	} while (0)
 
 void print_usage(void);
-void sigint();
+void sigint(int signum);
 int receive_command(int socket, char *buf);
 void state_connected();
 
@@ -519,12 +519,12 @@ void print_usage(void)
 	printf("\t-h prints this message\n");
 }
 
-void childdied()
+void childdied(int signum)
 {
 	wait(NULL);
 }
 
-void sigint()
+void sigint(int signum)
 {
 	if (verbose_flag)
 		PRINT_ERROR("received SIGINT\n");