diff --git a/pandas/core/arrays/sparse/dtype.py b/pandas/core/arrays/sparse/dtype.py
index 3b656705f5568..0124304727ab3 100644
--- a/pandas/core/arrays/sparse/dtype.py
+++ b/pandas/core/arrays/sparse/dtype.py
@@ -1,7 +1,7 @@
 """Sparse Dtype"""
 
 import re
-from typing import Any
+from typing import Any, Tuple
 
 import numpy as np
 
@@ -223,7 +223,7 @@ def construct_from_string(cls, string):
             raise TypeError(msg)
 
     @staticmethod
-    def _parse_subtype(dtype):
+    def _parse_subtype(dtype: str) -> Tuple[str, bool]:
         """
         Parse a string to get the subtype
 
@@ -249,7 +249,7 @@ def _parse_subtype(dtype):
         has_fill_value = False
         if m:
             subtype = m.groupdict()["subtype"]
-            has_fill_value = m.groupdict()["fill_value"] or has_fill_value
+            has_fill_value = bool(m.groupdict()["fill_value"])
         elif dtype == "Sparse":
             subtype = "float64"
         else: