diff --git a/colorpedia/inputs.py b/colorpedia/inputs.py
index 17be065..f93d65e 100644
--- a/colorpedia/inputs.py
+++ b/colorpedia/inputs.py
@@ -42,6 +42,8 @@ def normalize_degree_angle(value: Union[float, int]) -> float:
 
 
 def normalize_hex_code(value: str) -> str:
+    if isinstance(value, int):
+        value = str(value)
     if isinstance(value, str) and re.search(HEX_REGEX, value):
         return value if len(value) == 6 else "".join(c * 2 for c in value)
     raise InputValueError("hex code", f"a string matching {HEX_REGEX}")
diff --git a/tests/test_inputs.py b/tests/test_inputs.py
index ba6bcfe..dddd4f7 100644
--- a/tests/test_inputs.py
+++ b/tests/test_inputs.py
@@ -122,14 +122,14 @@ def test_normalize_degree_angle_bad_arg(bad_arg):
 
 @pytest.mark.parametrize(
     ("arg", "expected"),
-    (("ABC", "AABBCC"), ("ABCDEF", "ABCDEF"), ("FFFFFF", "FFFFFF")),
+    (("ABC", "AABBCC"), ("ABCDEF", "ABCDEF"), ("FFFFFF", "FFFFFF"), (212121, "212121")),
 )
 def test_normalize_hex_code(arg, expected):
     assert normalize_hex_code(arg) == expected
 
 
 @pytest.mark.parametrize(
-    "bad_arg", ("", "F", "FF", "FFFFFH", "#FFFFFF", True, False, max, None, [])
+    "bad_arg", ("", "F", "FFFFFH", "#FFFFFF", 212121.0, True, False, max, None, [])
 )
 def test_normalize_hex_code_bad_arg(bad_arg):
     with pytest.raises(InputValueError) as err: