diff --git a/src/event/ngx_event_openssl.h b/src/event/ngx_event_openssl.h
index 63cb333..66edc52 100644
--- a/src/event/ngx_event_openssl.h
+++ b/src/event/ngx_event_openssl.h
@@ -79,7 +79,7 @@
 ngx_chain_t *ngx_ssl_send_chain(ngx_connection_t *c, ngx_chain_t *in,
     off_t limit);
 ngx_int_t ngx_ssl_shutdown(ngx_connection_t *c);
-void ngx_ssl_error(ngx_uint_t level, ngx_log_t *log, ngx_err_t err,
+void ngx_cdecl ngx_ssl_error(ngx_uint_t level, ngx_log_t *log, ngx_err_t err,
     char *fmt, ...);
 void ngx_ssl_cleanup_ctx(void *data);