diff --git a/binding.gyp b/binding.gyp
index e9ec495..86eebc1 100644
--- a/binding.gyp
+++ b/binding.gyp
@@ -99,6 +99,7 @@
             'MACOSX_DEPLOYMENT_TARGET': '10.7',
             'OTHER_CPLUSPLUSFLAGS': [ '-std=c++14' ]
           },
+          'cflags': [ '-fvisibility=hidden '],
           'cflags_cc': [ '-std=c++14' ],
           'cflags!': [ '-fno-exceptions' ],
           'cflags_cc!': [ '-fno-exceptions' ],
diff --git a/src/main.cc b/src/main.cc
index 99f174f..9740d8c 100644
--- a/src/main.cc
+++ b/src/main.cc
@@ -110,7 +110,7 @@ static void InitDebug() {
 }
 #endif
 
-Napi::Object Pymp_Init(Env env, Object exports) {
+static Napi::Object PympInit(Env env, Object exports) {
 #ifdef DEBUG
   InitDebug();
 #endif
@@ -223,4 +223,4 @@ Napi::Object Pymp_Init(Env env, Object exports) {
   return exports;
 }
 
-NODE_API_MODULE(pymport, Pymp_Init)
+NODE_API_MODULE(pymport, PympInit)