diff --git a/TOOLS/alaw-gen.c b/TOOLS/alaw-gen.c
index e803ba3ccc..11b7385f66 100644
--- a/TOOLS/alaw-gen.c
+++ b/TOOLS/alaw-gen.c
@@ -3,7 +3,7 @@
 
 // sox -t raw -A -r 8000 -b alaw.alaw -t sw alaw.out
 
-int main(){
+int main(void){
 int i;
 FILE *f;
 
diff --git a/TOOLS/dump_mp4.c b/TOOLS/dump_mp4.c
index f0fc2dc631..7c67189c53 100644
--- a/TOOLS/dump_mp4.c
+++ b/TOOLS/dump_mp4.c
@@ -1,6 +1,6 @@
 #include <stdio.h>
 
-int main(){
+int main(void){
 int c;
 unsigned int head=-1;
 int pos=-3;