diff --git a/xwords4/android/app/build.gradle b/xwords4/android/app/build.gradle
index 08e3533d2..e40ac3c20 100644
--- a/xwords4/android/app/build.gradle
+++ b/xwords4/android/app/build.gradle
@@ -58,7 +58,7 @@ android {
     // Specify buildToolsVersion so gradle will inform when the
     // default changes and .travis.yml can be kept in sync
     buildToolsVersion '28.0.3'
-    ndkVersion '21.3.6528147'
+    ndkVersion '21.4.7075529'
     defaultConfig {
         // HostApduService requires 19. But is it a problem?
         minSdkVersion 14