diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c
index 2952c95fcf2..00ccea8d4c5 100644
--- a/Objects/unicodeobject.c
+++ b/Objects/unicodeobject.c
@@ -4962,7 +4962,7 @@ as well as any other name registerd with codecs.register_error that is\n\
 able to handle UnicodeDecodeErrors.");
 
 static PyObject *
-unicode_decode(PyStringObject *self, PyObject *args)
+unicode_decode(PyUnicodeObject *self, PyObject *args)
 {
     char *encoding = NULL;
     char *errors = NULL;