diff --git a/transformer_engine/pytorch/csrc/extensions/pybind.cpp b/transformer_engine/pytorch/csrc/extensions/pybind.cpp
index 7e9d114be8..c6bf7eb516 100644
--- a/transformer_engine/pytorch/csrc/extensions/pybind.cpp
+++ b/transformer_engine/pytorch/csrc/extensions/pybind.cpp
@@ -120,6 +120,7 @@ void init_grouped_tensor_extension() {
 }
 
 void init_extension() {
+  pybind11::gil_scoped_acquire gil;
   std::call_once(extension_init_flag, []() {
     init_float8_extension();
     init_mxfp8_extension();