diff --git a/go/pserver/cclient/test/CMakeLists.txt b/go/pserver/cclient/test/CMakeLists.txt
index de7ef6a47ac881daaedf461e337e61c74b927884..16f84648c1de3a8fdb4595c00bdb7608a152ded2 100644
--- a/go/pserver/cclient/test/CMakeLists.txt
+++ b/go/pserver/cclient/test/CMakeLists.txt
@@ -4,5 +4,8 @@ include_directories(${CMAKE_BINARY_DIR})
 
 add_executable(main main.c)
 add_dependencies(main client)
-set (CMAKE_EXE_LINKER_FLAGS "-pthread")
+
+if(APPLE)
+  set(CMAKE_EXE_LINKER_FLAGS "-framework CoreFoundation -framework Security")
+endif()
 target_link_libraries(main ${CMAKE_BINARY_DIR}/libclient.a)
diff --git a/go/pserver/cclient/test/main.c b/go/pserver/cclient/test/main.c
index c14037235c144e1193e0ed2a4c1b01787b92b202..f75a2110b947520dfec1265e56eaf2ba7ac3b51b 100644
--- a/go/pserver/cclient/test/main.c
+++ b/go/pserver/cclient/test/main.c
@@ -17,7 +17,7 @@ retry:
     paddle_parameter param;
     char name_a[] = "param_a";
     char name_b[] = "param_b";
-    char content[] = {0x00, 0x11, 0x22};
+    unsigned char content[] = {0x00, 0x11, 0x22};
     param.element_type = PADDLE_ELEMENT_TYPE_FLOAT32;
     param.name = name_a;
     param.content = content;
@@ -39,7 +39,7 @@ retry:
     fail();
   }
 
-  char content[] = {0x00, 0x11, 0x22};
+  unsigned char content[] = {0x00, 0x11, 0x22};
   paddle_gradient grads[2] = {
       {"param_a", PADDLE_ELEMENT_TYPE_INT32, content, 3},
       {"param_b", PADDLE_ELEMENT_TYPE_FLOAT32, content, 3}};