diff --git a/tools/caffe/CMakeLists.txt b/tools/caffe/CMakeLists.txt
index befa09e14..a6e035518 100644
--- a/tools/caffe/CMakeLists.txt
+++ b/tools/caffe/CMakeLists.txt
@@ -1,5 +1,5 @@
 
-find_package(Protobuf REQUIRED)
+find_package(Protobuf)
 
 if(PROTOBUF_FOUND)
     include_directories(${PROTOBUF_INCLUDE_DIR})