diff --git a/test/Wikiq_Unit_Test.py b/test/Wikiq_Unit_Test.py
index b1540a8..f1086f4 100644
--- a/test/Wikiq_Unit_Test.py
+++ b/test/Wikiq_Unit_Test.py
@@ -11,7 +11,7 @@ from pandas import DataFrame
 from pandas.testing import assert_frame_equal, assert_series_equal
 from io import StringIO
 import tracemalloc
-from typing import Final
+from typing import Final, Union
 
 # Make references to files and wikiq relative to this file, not to the current working directory.
 TEST_DIR: Final[str] = os.path.dirname(os.path.realpath(__file__))
@@ -42,7 +42,7 @@ class WikiqTester:
     def __init__(self,
                  wiki: str,
                  case_name: str,
-                 suffix: str | None = None,
+                 suffix: Union[str, None] = None,
                  in_compression: str = "bz2",
                  baseline_format: str = "tsv",
                  out_format: str = "tsv",
diff --git a/wikiq b/wikiq
index c5e83a6..75d8b0d 100755
--- a/wikiq
+++ b/wikiq
@@ -338,7 +338,7 @@ class WikiqParser:
         page_count = 0
         rev_count = 0
 
-        writer: pq.ParquetWriter | pc.CSVWriter
+        writer: Union[pq.ParquetWriter, pc.CSVWriter]
 
         schema = table.schema()
         schema = schema.append(pa.field('revert', pa.bool_(), nullable=True))