diff --git a/contrib/CMakeLists.txt b/contrib/CMakeLists.txt
index e3e48ac3a1..a963e4497f 100644
--- a/contrib/CMakeLists.txt
+++ b/contrib/CMakeLists.txt
@@ -399,7 +399,7 @@ if(${BUILD_WITH_COS})
     INCLUDE_DIRECTORIES($ENV{HOME}/.cos-local.1/include)
     MESSAGE("$ENV{HOME}/.cos-local.1/include")
 
-    set(CMAKE_BUILD_TYPE debug)
+    set(CMAKE_BUILD_TYPE Release)
     set(ORIG_CMAKE_PROJECT_NAME ${CMAKE_PROJECT_NAME})
     set(CMAKE_PROJECT_NAME cos_c_sdk)