diff --git a/programs/fuzz/common.c b/programs/fuzz/common.c
index 56b9a13..96a24f7 100644
--- a/programs/fuzz/common.c
+++ b/programs/fuzz/common.c
@@ -13,7 +13,7 @@
 }
 #endif
 
-void dummy_init()
+void dummy_init(void)
 {
 #if defined(MBEDTLS_PLATFORM_TIME_ALT)
     mbedtls_platform_set_time(dummy_constant_time);
diff --git a/programs/fuzz/common.h b/programs/fuzz/common.h
index 6b5b515..d5b098f 100644
--- a/programs/fuzz/common.h
+++ b/programs/fuzz/common.h
@@ -19,7 +19,7 @@
 #if defined(MBEDTLS_HAVE_TIME)
 mbedtls_time_t dummy_constant_time(mbedtls_time_t *time);
 #endif
-void dummy_init();
+void dummy_init(void);
 
 int dummy_send(void *ctx, const unsigned char *buf, size_t len);
 int fuzz_recv(void *ctx, unsigned char *buf, size_t len);