diff --git a/tests/samples.txt b/tests/samples.txt
index 240f476..ed47784 100644
--- a/tests/samples.txt
+++ b/tests/samples.txt
@@ -27,6 +27,7 @@
   dict1: <Test #hex{b8 7161 31 5162 01 93313233 6163 b2 7a66697273742d6e616d65 59456c697a6162657468 b2 777375726e616d65 59426c61636b77656c6c} { a: 1 "b": #true [1 2 3]: c { first-name: "Elizabeth" }: { surname: "Blackwell" } }>
   dict2: @"Missing close brace" <ParseShort "{ a: b, c: d ">
   dict2a: @"Missing close brace" <ParseShort "{">
+  dict3: @"Duplicate key" <ParseError "{ a: 1, a: 2 }">
   double1: <Test #hex{033ff0000000000000} 1.0>
   double2: <Test #hex{03fe3cb7b759bf0426} -1.202e300>
   float1: <Test #hex{023f800000} 1.0f>