1 files changed, 10 insertions, 0 deletions
diff --git a/Objects/stringlib/string_format.h b/Objects/stringlib/string_format.h
index 4053545..c1a6d1d 100644
--- a/Objects/stringlib/string_format.h
+++ b/Objects/stringlib/string_format.h
@@ -1192,6 +1192,11 @@ formatter_parser(PyObject *ignored, STRINGLIB_OBJECT *self)
 {
     formatteriterobject *it;
 
+    if (!PyUnicode_Check(self)) {
+        PyErr_Format(PyExc_TypeError, "expected str, got %s", Py_TYPE(self)->tp_name);
+        return NULL;
+    }
+
     it = PyObject_New(formatteriterobject, &PyFormatterIter_Type);
     if (it == NULL)
         return NULL;
@@ -1332,6 +1337,11 @@ formatter_field_name_split(PyObject *ignored, STRINGLIB_OBJECT *self)
     PyObject *first_obj = NULL;
     PyObject *result = NULL;
 
+    if (!PyUnicode_Check(self)) {
+        PyErr_Format(PyExc_TypeError, "expected str, got %s", Py_TYPE(self)->tp_name);
+        return NULL;
+    }
+
     it = PyObject_New(fieldnameiterobject, &PyFieldNameIter_Type);
     if (it == NULL)
         return NULL;