diff --git a/include/mbedtls/ssl_cookie.h b/include/mbedtls/ssl_cookie.h
index afeb07b..ec54f61 100644
--- a/include/mbedtls/ssl_cookie.h
+++ b/include/mbedtls/ssl_cookie.h
@@ -55,9 +55,7 @@
 /**
  * \brief          Setup cookie context (generate keys)
  */
-int mbedtls_ssl_cookie_setup(mbedtls_ssl_cookie_ctx *ctx,
-                             int (*f_rng)(void *, unsigned char *, size_t),
-                             void *p_rng);
+int mbedtls_ssl_cookie_setup(mbedtls_ssl_cookie_ctx *ctx);
 
 /**
  * \brief          Set expiration delay for cookies