diff --git a/include/bmi/Bmi_C_Adapter.hpp b/include/bmi/Bmi_C_Adapter.hpp
index d736cf5329..5dcabbf0ad 100755
--- a/include/bmi/Bmi_C_Adapter.hpp
+++ b/include/bmi/Bmi_C_Adapter.hpp
@@ -562,7 +562,7 @@ namespace models {
             inline void construct_and_init_backing_model_for_type() {
                 if (model_initialized)
                     return;
-                bmi_model = std::make_shared<C_Bmi>(C_Bmi());
+                bmi_model = std::make_unique<C_Bmi>(C_Bmi());
                 execModuleRegistration();
                 int init_result = bmi_model->initialize(bmi_model.get(), bmi_init_config.c_str());
                 if (init_result != BMI_SUCCESS) {
@@ -643,7 +643,7 @@ namespace models {
             friend class ::Bmi_C_Adapter_Test;
 
             /** Pointer to backing BMI model instance. */
-            std::shared_ptr<C_Bmi> bmi_model = nullptr;
+            std::unique_ptr<C_Bmi> bmi_model = nullptr;
 
         };
 
diff --git a/include/bmi/Bmi_Fortran_Adapter.hpp b/include/bmi/Bmi_Fortran_Adapter.hpp
index 00bef70f7f..c21a77c13d 100644
--- a/include/bmi/Bmi_Fortran_Adapter.hpp
+++ b/include/bmi/Bmi_Fortran_Adapter.hpp
@@ -498,7 +498,7 @@ namespace models {
             inline void construct_and_init_backing_model_for_fortran() {
                 if (model_initialized)
                     return;
-                bmi_model = std::make_shared<Bmi_Fortran_Handle_Wrapper>(Bmi_Fortran_Handle_Wrapper());
+                bmi_model = std::make_unique<Bmi_Fortran_Handle_Wrapper>(Bmi_Fortran_Handle_Wrapper());
                 dynamic_library_load();
                 execModuleRegistration();
                 int init_result = initialize(&bmi_model->handle, bmi_init_config.c_str());
@@ -805,7 +805,7 @@ namespace models {
 
         private:
             /** Pointer to backing BMI model instance. */
-            std::shared_ptr<Bmi_Fortran_Handle_Wrapper> bmi_model = nullptr;
+            std::unique_ptr<Bmi_Fortran_Handle_Wrapper> bmi_model = nullptr;
 
         };
     }
diff --git a/include/bmi/Bmi_Py_Adapter.hpp b/include/bmi/Bmi_Py_Adapter.hpp
index 377e8a35d2..773013745d 100644
--- a/include/bmi/Bmi_Py_Adapter.hpp
+++ b/include/bmi/Bmi_Py_Adapter.hpp
@@ -662,7 +662,7 @@ namespace models {
                     // This is a class object for the BMI module Python class
                     py::object bmi_py_class = utils::ngenPy::InterpreterUtil::getPyModule(moduleComponents);
                     // This is the actual backing model object
-                    bmi_model = std::make_shared<py::object>(bmi_py_class());
+                    bmi_model = std::make_unique<py::object>(bmi_py_class());
                     bmi_model->attr("initialize")(bmi_init_config);
                 }
                 catch (std::runtime_error& e){ //Catch specific exception types so the type/message don't get erased
@@ -773,7 +773,7 @@ namespace models {
 
         protected:
             /** Pointer to backing BMI model instance. */
-            std::shared_ptr<py::object> bmi_model = nullptr;
+            std::unique_ptr<py::object> bmi_model = nullptr;
 
         };