diff --git a/libraries/build_protobuf.sh b/libraries/build_protobuf.sh
index edadb09..e1311bc 100755
--- a/libraries/build_protobuf.sh
+++ b/libraries/build_protobuf.sh
@@ -1,4 +1,6 @@
-cd protobuf/build
+cd protobuf
+git checkout 3.5.1.1
+cd build
 cmake ../cmake/ -Dprotobuf_BUILD_TESTS=OFF -DCMAKE_CXX_FLAGS="-std=c++11 -fPIC ${CXX_FLAGS}" -DCMAKE_C_FLAGS="${C_FLAGS}" ${CMAKE_OPTIONS}
 make ${CMAKE_MAKE_OPTIONS}
 sudo make install