diff --git a/tests/oss-fuzz/build.sh b/tests/oss-fuzz/build.sh
index e7f6738d46..80173e3a90 100755
--- a/tests/oss-fuzz/build.sh
+++ b/tests/oss-fuzz/build.sh
@@ -35,5 +35,10 @@ $CXX $CXXFLAGS -std=c++11 -I../include \
     $LIB_FUZZING_ENGINE libavif.a ../ext/dav1d/build/src/libdav1d.a \
     ../ext/libyuv/build/libyuv.a
 
-# copy seed corpus
-cp $SRC/avif_decode_seed_corpus.zip $OUT/
+# WIP: copy seed corpus for fuzztest tests
+mkdir $OUT/corpus
+unzip $SRC/avif_decode_seed_corpus.zip -d $OUT/corpus
+cp $SRC/libavif/tests/data/* $OUT/corpus
+
+# create a bigger seed corpus for avif_decode_fuzzer
+zip -j $OUT/avif_decode_fuzzer_seed_corpus.zip $OUT/corpus/*