diff --git a/xwords4/android/XWords4-sms/jni/Android.mk b/xwords4/android/XWords4-sms/jni/Android.mk
index 0793fc04a..8b21ce84e 100644
--- a/xwords4/android/XWords4-sms/jni/Android.mk
+++ b/xwords4/android/XWords4-sms/jni/Android.mk
@@ -33,6 +33,7 @@ local_DEFINES += \
 	-DFEATURE_TRAY_EDIT \
 	-DMAX_ROWS=32 \
 	-DHASH_STREAM \
+	-DXWFEATURE_BASE64 \
 	-DINITIAL_CLIENT_VERS=2 \
 	-DNODE_CAN_4 \
 	-DRELAY_ROOM_DEFAULT=\"\" \