diff --git a/Modules/_posixsubprocess.c b/Modules/_posixsubprocess.c
index a327fc5..800b301 100644
--- a/Modules/_posixsubprocess.c
+++ b/Modules/_posixsubprocess.c
@@ -549,7 +549,9 @@
     int need_to_reenable_gc = 0;
     char *const *exec_array, *const *argv = NULL, *const *envp = NULL;
     Py_ssize_t arg_num;
+#ifdef WITH_THREAD
     int import_lock_held = 0;
+#endif
 
     if (!PyArg_ParseTuple(
             args, "OOpOOOiiiiiiiiiiO:fork_exec",
@@ -644,8 +646,10 @@
         preexec_fn_args_tuple = PyTuple_New(0);
         if (!preexec_fn_args_tuple)
             goto cleanup;
+#ifdef WITH_THREAD
         _PyImport_AcquireLock();
         import_lock_held = 1;
+#endif
     }
 
     if (cwd_obj != Py_None) {
@@ -688,12 +692,14 @@
         /* Capture the errno exception before errno can be clobbered. */
         PyErr_SetFromErrno(PyExc_OSError);
     }
-    if (preexec_fn != Py_None &&
-        _PyImport_ReleaseLock() < 0 && !PyErr_Occurred()) {
+#ifdef WITH_THREAD
+    if (preexec_fn != Py_None
+        && _PyImport_ReleaseLock() < 0 && !PyErr_Occurred()) {
         PyErr_SetString(PyExc_RuntimeError,
                         "not holding the import lock");
     }
     import_lock_held = 0;
+#endif
 
     /* Parent process */
     if (envp)
@@ -716,8 +722,10 @@
     return PyLong_FromPid(pid);
 
 cleanup:
+#ifdef WITH_THREAD
     if (import_lock_held)
         _PyImport_ReleaseLock();
+#endif
     if (envp)
         _Py_FreeCharPArray(envp);
     if (argv)
diff --git a/Modules/socketmodule.c b/Modules/socketmodule.c
index d9c70f8..bae9634 100644
--- a/Modules/socketmodule.c
+++ b/Modules/socketmodule.c
@@ -719,8 +719,10 @@
     int deadline_initialized = 0;
     int res;
 
+#ifdef WITH_THREAD
     /* sock_call() must be called with the GIL held. */
     assert(PyGILState_Check());
+#endif
 
     /* outer loop to retry select() when select() is interrupted by a signal
        or to retry select()+sock_func() on false positive (see above) */
diff --git a/Python/fileutils.c b/Python/fileutils.c
index bccd321..079918c 100644
--- a/Python/fileutils.c
+++ b/Python/fileutils.c
@@ -986,8 +986,10 @@
 int
 _Py_open(const char *pathname, int flags)
 {
+#ifdef WITH_THREAD
     /* _Py_open() must be called with the GIL held. */
     assert(PyGILState_Check());
+#endif
     return _Py_open_impl(pathname, flags, 1);
 }
 
@@ -1080,7 +1082,9 @@
     wchar_t wmode[10];
     int usize;
 
+#ifdef WITH_THREAD
     assert(PyGILState_Check());
+#endif
 
     if (!PyUnicode_Check(path)) {
         PyErr_Format(PyExc_TypeError,
@@ -1108,7 +1112,9 @@
     PyObject *bytes;
     char *path_bytes;
 
+#ifdef WITH_THREAD
     assert(PyGILState_Check());
+#endif
 
     if (!PyUnicode_FSConverter(path, &bytes))
         return NULL;