diff --git a/specs.md b/specs.md
index 50f2288..7514ad6 100644
--- a/specs.md
+++ b/specs.md
@@ -1853,12 +1853,15 @@ When switching on a `Type` value (from `type_of`), category keywords match all r
 ```sx
 type := type_of(val);
 if type == {
-    case int: result = int_to_string(xx val);
+    case int: {
+        if type_is_unsigned(type) { result = uint_to_string(xx val); }
+        else { result = int_to_string(xx val); }
+    }
     case struct: result = struct_to_string(cast(type) val);
     case enum: result = enum_to_string(cast(type) val);
 }
 ```
-Available categories: `int`, `float`, `bool`, `string`, `struct`, `enum`, `vector`, `array`, `slice`, `pointer`, `type`.
+Available categories: `int`, `float`, `bool`, `string`, `struct`, `enum`, `vector`, `array`, `slice`, `pointer`, `type`. The `int` arm branches on signedness — `type_is_unsigned(type)` routes unsigned types to their unsigned-decimal formatter, so values like `u64.max` print as `18446744073709551615` rather than `-1`.
 
 > Note: `case enum:` matches both payload-less enums and tagged enums (enums with payloads). C-style untagged unions are not registered with the Any type system and cannot be matched by category.