diff --git a/tests/unit/test_write_json_files.py b/tests/unit/test_write_json_files.py
index dc9e18d3..b0a3c6a0 100644
--- a/tests/unit/test_write_json_files.py
+++ b/tests/unit/test_write_json_files.py
@@ -757,7 +757,7 @@ def test_max_differences(self):
                     "COMPARE": ["C", "C"],
                     "VLABEL": ["", ""],
                     "_DATAROLE_": ["role", "role"],
-                    "maxdiff": [0, 1],
+                    "maxdiff": ["0", "1"],
                 }
             ),
         )
@@ -771,7 +771,7 @@ def test_max_differences(self):
                     "COMPARE": ["C", "C"],
                     "VLABEL": ["", ""],
                     "_DATAROLE_": ["TEST", "TEST"],
-                    "maxdiff": [0, 1],
+                    "maxdiff": ["0", "1"],
                 }
             ),
         )