diff --git a/src/script/lua_api/l_util.cpp b/src/script/lua_api/l_util.cpp
index d24d070ca..0d9883bf7 100644
--- a/src/script/lua_api/l_util.cpp
+++ b/src/script/lua_api/l_util.cpp
@@ -44,6 +44,11 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "util/png.h"
 #include <cstdio>
 
+// only available in zstd 1.3.5+
+#ifndef ZSTD_CLEVEL_DEFAULT
+#define ZSTD_CLEVEL_DEFAULT 3
+#endif
+
 // log([level,] text)
 // Writes a line to the logger.
 // The one-argument version logs to LL_NONE.