diff --git a/test/unit/util/test_json.py b/test/unit/util/test_json.py
new file mode 100644
index 00000000000..dc1a3432d50
--- /dev/null
+++ b/test/unit/util/test_json.py
@@ -0,0 +1,25 @@
+from decimal import Decimal
+
+import pytest
+
+from galaxy.util.json import (
+    safe_dumps,
+    swap_inf_nan,
+)
+
+
+@pytest.mark.parametrize(
+    "val,expected_val",
+    [
+        (float("inf"), "__Infinity__"),
+        (float("-inf"), "__-Infinity__"),
+        (float("NaN"), "__NaN__"),
+        (Decimal("1"), "1"),
+    ],
+)
+def test_swap_inf_nan(val, expected_val):
+    assert swap_inf_nan(val) == expected_val
+
+
+def test_safe_dumps():
+    assert safe_dumps({"a": Decimal("0.1")}) == """{"a": "0.1"}"""