diff --git a/plugins/python/pyloader.c b/plugins/python/pyloader.c
index ceb595df..19882219 100644
--- a/plugins/python/pyloader.c
+++ b/plugins/python/pyloader.c
@@ -539,6 +539,7 @@ PyObject *uwsgi_mount_loader(void *arg1) {
 
 	if ( !strcmp(what+strlen(what)-3, ".py") || !strcmp(what+strlen(what)-5, ".wsgi")) {
 		callable = uwsgi_file_loader((void *)what);
+		if (!callable) exit(1);
 	}
 	else if (!strcmp(what+strlen(what)-4, ".ini")) {
 		callable = uwsgi_paste_loader((void *)what);
@@ -605,30 +606,44 @@ PyObject *uwsgi_file_loader(void *arg1) {
 	char *callable = up.callable;
 	if (!callable) callable = "application";
 
-	wsgi_file_module = uwsgi_pyimport_by_filename(uwsgi_concat2("uwsgi_file_", uwsgi_pythonize(filename)), filename);
+	char *py_filename = uwsgi_concat2("uwsgi_file_", uwsgi_pythonize(filename));
+
+	wsgi_file_module = uwsgi_pyimport_by_filename(py_filename, filename);
 	if (!wsgi_file_module) {
 		PyErr_Print();
-		exit(1);
+		free(py_filename);
+		return NULL;
 	}
 
 	wsgi_file_dict = PyModule_GetDict(wsgi_file_module);
 	if (!wsgi_file_dict) {
 		PyErr_Print();
-		exit(1);
+		Py_DECREF(wsgi_file_module);
+		free(py_filename);
+		return NULL;
 	}
 
 	wsgi_file_callable = PyDict_GetItemString(wsgi_file_dict, callable);
 	if (!wsgi_file_callable) {
 		PyErr_Print();
+		Py_DECREF(wsgi_file_dict);
+		Py_DECREF(wsgi_file_module);
+                free(py_filename);
 		uwsgi_log( "unable to find \"application\" callable in file %s\n", filename);
-		exit(1);
+		return NULL;
 	}
 
 	if (!PyFunction_Check(wsgi_file_callable) && !PyCallable_Check(wsgi_file_callable)) {
 		uwsgi_log( "\"application\" must be a callable object in file %s\n", filename);
-		exit(1);
+		Py_DECREF(wsgi_file_callable);
+		Py_DECREF(wsgi_file_dict);
+		Py_DECREF(wsgi_file_module);
+                free(py_filename);
+		return NULL;
 	}
 
+        free(py_filename);
+
 	return wsgi_file_callable;
 
 }
diff --git a/plugins/python/python_plugin.c b/plugins/python/python_plugin.c
index 8d42c368..dcc8af82 100644
--- a/plugins/python/python_plugin.c
+++ b/plugins/python/python_plugin.c
@@ -1097,6 +1097,9 @@ void uwsgi_python_enable_threads() {
 	up.gil_get = gil_real_get;
 	up.gil_release = gil_real_release;
 
+	up.swap_ts = simple_threaded_swap_ts;
+	up.reset_ts = simple_threaded_reset_ts;
+
 	if (uwsgi.threads > 1) {
 		up.swap_ts = threaded_swap_ts;
 		up.reset_ts = threaded_reset_ts;
diff --git a/plugins/python/uwsgi_python.h b/plugins/python/uwsgi_python.h
index f1e9ae48..97123d8a 100644
--- a/plugins/python/uwsgi_python.h
+++ b/plugins/python/uwsgi_python.h
@@ -259,8 +259,10 @@ PyObject *uwsgi_pyimport_by_filename(char *, char *);
 
 void threaded_swap_ts(struct wsgi_request *, struct uwsgi_app *);
 void simple_swap_ts(struct wsgi_request *, struct uwsgi_app *);
+void simple_threaded_swap_ts(struct wsgi_request *, struct uwsgi_app *);
 void threaded_reset_ts(struct wsgi_request *, struct uwsgi_app *);
 void simple_reset_ts(struct wsgi_request *, struct uwsgi_app *);
+void simple_threaded_reset_ts(struct wsgi_request *, struct uwsgi_app *);
 
 int uwsgi_python_profiler_call(PyObject *, PyFrameObject *, int, PyObject *);
 
diff --git a/plugins/python/wsgi_handlers.c b/plugins/python/wsgi_handlers.c
index ce4fe62d..d19614f5 100644
--- a/plugins/python/wsgi_handlers.c
+++ b/plugins/python/wsgi_handlers.c
@@ -599,3 +599,23 @@ void simple_swap_ts(struct wsgi_request *wsgi_req, struct uwsgi_app *wi) {
                 PyThreadState_Swap(wi->interpreter);
 	}
 }
+
+void simple_threaded_reset_ts(struct wsgi_request *wsgi_req, struct uwsgi_app *wi) {
+	if (uwsgi.single_interpreter == 0 && wi->interpreter != up.main_thread) {
+        	// restoring main interpreter
+		UWSGI_GET_GIL
+                PyThreadState_Swap(up.main_thread);
+		UWSGI_RELEASE_GIL
+	}
+}
+
+
+void simple_threaded_swap_ts(struct wsgi_request *wsgi_req, struct uwsgi_app *wi) {
+
+	if (uwsgi.single_interpreter == 0 && wi->interpreter != up.main_thread) {
+                // set the interpreter
+		UWSGI_GET_GIL
+                PyThreadState_Swap(wi->interpreter);
+		UWSGI_RELEASE_GIL
+	}
+}