diff --git a/metadata/org.sufficientlysecure.viewer.txt b/metadata/org.sufficientlysecure.viewer.txt
index f3c85d703d..0509097ea3 100644
--- a/metadata/org.sufficientlysecure.viewer.txt
+++ b/metadata/org.sufficientlysecure.viewer.txt
@@ -49,6 +49,7 @@ Build:2.6,2600
     gradle=yes
     buildjni=yes
     submodules=yes
+    scandelete=document-viewer/jni/mupdf/mupdf/build/debug/
     prebuild=pushd jni/mupdf/mupdf && ANDROID_NDK=$$NDK$$ make generate && \
         patch -p1 < ../overrides/fonts.patch && \
         patch -p1 < ../overrides/nightmode_slowcmyk.patch
@@ -60,6 +61,7 @@ Build:2.6,2601
     gradle=yes
     buildjni=yes
     submodules=yes
+    scandelete=document-viewer/jni/mupdf/mupdf/build/debug/
     prebuild=ANDROID_NDK=$$NDK$$ ./init.sh
 
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