diff -r 23ab1197df0b Python/_warnings.c
--- a/Python/_warnings.c	Wed Nov 19 13:21:40 2014 +0200
+++ b/Python/_warnings.c	Wed Nov 19 16:41:32 2014 +0100
@@ -520,26 +520,32 @@ setup_context(Py_ssize_t stack_level, Py
 
     *module = NULL;
 
-    /* Setup registry. */
-    assert(globals != NULL);
-    assert(PyDict_Check(globals));
-    *registry = PyDict_GetItemString(globals, "__warningregistry__");
-    if (*registry == NULL) {
-        int rc;
+    /* during Python finalization, warnings may be emited after interp->sysdict
+       is cleared: see issue #22898 */
+    if (globals != NULL) {
+        /* Setup registry. */
+        assert(PyDict_Check(globals));
+        *registry = PyDict_GetItemString(globals, "__warningregistry__");
+        if (*registry == NULL) {
+            int rc;
 
-        *registry = PyDict_New();
-        if (*registry == NULL)
-            return 0;
+            *registry = PyDict_New();
+            if (*registry == NULL)
+                return 0;
 
-         rc = PyDict_SetItemString(globals, "__warningregistry__", *registry);
-         if (rc < 0)
-            goto handle_error;
+             rc = PyDict_SetItemString(globals, "__warningregistry__", *registry);
+             if (rc < 0)
+                goto handle_error;
+        }
+        else
+            Py_INCREF(*registry);
+
+        /* Setup module. */
+        *module = PyDict_GetItemString(globals, "__name__");
     }
     else
-        Py_INCREF(*registry);
+        *module = NULL;
 
-    /* Setup module. */
-    *module = PyDict_GetItemString(globals, "__name__");
     if (*module == NULL) {
         *module = PyUnicode_FromString("<string>");
         if (*module == NULL)
@@ -549,7 +555,10 @@ setup_context(Py_ssize_t stack_level, Py
         Py_INCREF(*module);
 
     /* Setup filename. */
-    *filename = PyDict_GetItemString(globals, "__file__");
+    if (globals != NULL)
+        *filename = PyDict_GetItemString(globals, "__file__");
+    else
+        *filename = NULL;
     if (*filename != NULL && PyUnicode_Check(*filename)) {
         Py_ssize_t len;
         int kind;