diff --git a/sysdata/libraries/stn/src/formatters.hb b/sysdata/libraries/stn/src/formatters.hb
index cfc418968..c60d2a794 100644
--- a/sysdata/libraries/stn/src/formatters.hb
+++ b/sysdata/libraries/stn/src/formatters.hb
@@ -90,7 +90,7 @@ format_inner := fn($T: type, v: T, str: ^u8, opts: FormatOptions): uint {
 		return @inline(format_bool, v, str)
 	} else if float(T) {
 		return @inline(format_float, T, v, str, opts.decimal_digits)
-	} else {
+	} else if !primitive(T) {
 		i := 0
 		// name := @nameof(T)
 		// len := string.length(name)
@@ -112,8 +112,9 @@ format_inner := fn($T: type, v: T, str: ^u8, opts: FormatOptions): uint {
 			i += 1
 		}
 		return len
+	} else {
+		panic("Unsupported formatter type\0")
 	}
-	panic("Unsupported formatter type\0")
 }
 
 /* TODO: