diff --git a/projects/sentencepiece/build.sh b/projects/sentencepiece/build.sh
index c11826b481b8..020c75cc9e70 100755
--- a/projects/sentencepiece/build.sh
+++ b/projects/sentencepiece/build.sh
@@ -23,7 +23,7 @@ make -j $(nproc)
 make install
 
 # build fuzzers
-for fuzzer in $(find $SRC -name '*_fuzzer.cc'); do
+for fuzzer in $(find $SRC -name '*_fuzzer.cc' | grep -v 'third_party'); do
   fuzz_basename=$(basename -s .cc $fuzzer)
   $CXX $CXXFLAGS -std=c++17 -I. -I$SRC/sentencepiece \
       -I$SRC/sentencepiece/src \