diff --git a/tools_common.c b/tools_common.c
index e243a9157..7e2221712 100644
--- a/tools_common.c
+++ b/tools_common.c
@@ -140,7 +140,7 @@ static const VpxInterface vpx_encoders[] = {
 #endif
 };
 
-int get_vpx_encoder_count() {
+int get_vpx_encoder_count(void) {
   return sizeof(vpx_encoders) / sizeof(vpx_encoders[0]);
 }
 
diff --git a/tools_common.h b/tools_common.h
index b92980aba..db6e268a8 100644
--- a/tools_common.h
+++ b/tools_common.h
@@ -131,7 +131,7 @@ typedef struct VpxInterface {
   vpx_codec_iface_t *(*const codec_interface)();
 } VpxInterface;
 
-int get_vpx_encoder_count();
+int get_vpx_encoder_count(void);
 const VpxInterface *get_vpx_encoder_by_index(int i);
 const VpxInterface *get_vpx_encoder_by_name(const char *name);