diff --git a/metadata/org.sufficientlysecure.viewer.txt b/metadata/org.sufficientlysecure.viewer.txt
index 4a95dbefa6..02f2f8de80 100644
--- a/metadata/org.sufficientlysecure.viewer.txt
+++ b/metadata/org.sufficientlysecure.viewer.txt
@@ -48,6 +48,10 @@ Build:2.6,2600
     subdir=document-viewer
     gradle=yes
     buildjni=yes
+    submodules=yes
+    prebuild=pushd jni/mupdf/mupdf && ANDROID_NDK=$$NDK$$ make generate && \
+        patch -p1 < ../overrides/fonts.patch && \
+        patch -p1 < ../overrides/nightmode_slowcmyk.patch
 
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