diff --git a/Parser/lexer/lexer.c b/Parser/lexer/lexer.c
index 8c868593f944c8..dbbb94a407c81d 100644
--- a/Parser/lexer/lexer.c
+++ b/Parser/lexer/lexer.c
@@ -329,11 +329,7 @@ verify_identifier(struct tok_state *tok)
         return 0;
     }
     Py_ssize_t invalid = _PyUnicode_ScanIdentifier(s);
-    if (invalid < 0) {
-        Py_DECREF(s);
-        tok->done = E_ERROR;
-        return 0;
-    }
+    assert(invalid >= 0);
     assert(PyUnicode_GET_LENGTH(s) > 0);
     if (invalid < PyUnicode_GET_LENGTH(s)) {
         Py_UCS4 ch = PyUnicode_READ_CHAR(s, invalid);