diff -r 62235755609f Modules/socketmodule.c
--- a/Modules/socketmodule.c	Mon Aug 03 10:39:09 2015 +1200
+++ b/Modules/socketmodule.c	Mon Aug 03 10:55:26 2015 +0200
@@ -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 -r 62235755609f Python/fileutils.c
--- a/Python/fileutils.c	Mon Aug 03 10:39:09 2015 +1200
+++ b/Python/fileutils.c	Mon Aug 03 10:55:26 2015 +0200
@@ -987,7 +987,9 @@
 _Py_open(const char *pathname, int flags)
 {
     /* _Py_open() must be called with the GIL held. */
+#ifdef WITH_THREAD
     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;