diff --git a/metadata/org.eehouse.android.xw4.yml b/metadata/org.eehouse.android.xw4.yml
index f694f3c09d..9fe1ee6636 100644
--- a/metadata/org.eehouse.android.xw4.yml
+++ b/metadata/org.eehouse.android.xw4.yml
@@ -402,6 +402,7 @@ Builds:
     prebuild:
       - sed -i -e '/\/\/ rm-for-fdroid$/d' {..,.}/build.gradle
       - sed -i -e '/com.google.gms/d' build.gradle
+    ndk: r21
     gradleprops:
       - forFDroid