diff --git a/library/ssl_srv.c b/library/ssl_srv.c
index 4fa92fe..4601574 100644
--- a/library/ssl_srv.c
+++ b/library/ssl_srv.c
@@ -2774,7 +2774,7 @@
 
 #if defined(MBEDTLS_HAVE_TIME)
     t = mbedtls_time( NULL );
-    p = mbedtls_platform_put_uint32_be( p, t );
+    p = mbedtls_platform_put_uint32_be( p, (uint32_t) t );
 
     MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, current time: %lu", t ) );
 #else