diff -uNr openvpn-2.4.7/src/openvpn/options.c openvpn-2.4.7.mod/src/openvpn/options.c
--- openvpn-2.4.7/src/openvpn/options.c	2019-02-20 14:28:23.000000000 +0200
+++ openvpn-2.4.7.mod/src/openvpn/options.c	2019-09-18 14:41:05.337638310 +0300
@@ -898,7 +898,7 @@
     o->tmp_dir = getenv("TMPDIR");
     if (!o->tmp_dir)
     {
-        o->tmp_dir = "/tmp";
+        o->tmp_dir = "@TERMUX_PREFIX@/tmp";
     }
 #endif /* _WIN32 */
 #endif /* P2MP_SERVER */