diff --git a/include/mscclpp/env.hpp b/include/mscclpp/env.hpp
index 6a797e7d..6708628b 100644
--- a/include/mscclpp/env.hpp
+++ b/include/mscclpp/env.hpp
@@ -31,7 +31,7 @@ class Env {
   const std::string npkitDumpDir;
   const bool cudaIpcUseDefaultStream;
 
- protected:
+ private:
   Env();
 
   friend std::shared_ptr<Env> env();