--- a/make/mapfiles/libnio/mapfile-macosx	Tue Mar 27 13:48:16 2018 -0400
+++ b/make/mapfiles/libnio/mapfile-macosx	Tue Mar 27 19:29:46 2018 +0100
@@ -70,6 +70,7 @@
 		Java_sun_nio_ch_InheritedChannel_soType0;
                 Java_sun_nio_ch_IOUtil_configureBlocking;
                 Java_sun_nio_ch_IOUtil_drain;
+                Java_sun_nio_ch_IOUtil_drain1;
                 Java_sun_nio_ch_IOUtil_fdVal;
                 Java_sun_nio_ch_IOUtil_fdLimit;
                 Java_sun_nio_ch_IOUtil_initIDs;