diff --git a/metadata/com.artifex.mupdf.viewer.app.yml b/metadata/com.artifex.mupdf.viewer.app.yml
index dcc9e1b854..add300369d 100644
--- a/metadata/com.artifex.mupdf.viewer.app.yml
+++ b/metadata/com.artifex.mupdf.viewer.app.yml
@@ -154,7 +154,7 @@ Builds:
     scandelete:
       - jni/libmupdf/thirdparty
     build: make -C ../jni/libmupdf generate
-    ndk: r21
+    ndk: r21d
 
 MaintainerNotes: |-
     Upstream builds separate APKs for all target architectures supported by NDK