diff --git a/server/tools/scripts/construct/build_pb.py b/server/tools/scripts/construct/build_pb.py
index 466f960..dbb591e 100644
--- a/server/tools/scripts/construct/build_pb.py
+++ b/server/tools/scripts/construct/build_pb.py
@@ -36,7 +36,7 @@ def need_rebuild():
             return True
         s1 = os.stat(proto_name + '.pb.cc')
         s2 = os.stat('../tools/protobuild/' + proto_name + '.proto')
-        if s1.st_mtime < s2.st_mtime:
+        if s1.st_size <= 0 or s1.st_mtime < s2.st_mtime:
             return True
     return False
 
diff --git a/server/wsproxy/CMakeLists.txt b/server/wsproxy/CMakeLists.txt
index 456f7c8..07fe17f 100644
--- a/server/wsproxy/CMakeLists.txt
+++ b/server/wsproxy/CMakeLists.txt
@@ -43,6 +43,12 @@ aux_source_directory(../../third_party/framework/cpp
   SRC_LIST
 )
 
+execute_process(
+  COMMAND touch -a ss_proto.pb.h
+  COMMAND touch -a ss_proto.pb.cc
+  COMMAND touch -a ss_msgid.pb.h
+  COMMAND touch -a ss_msgid.pb.cc
+  )
 aux_source_directory(.
   SRC_LIST
 )