diff --git a/msgpack/src/test/scala/fs2/data/msgpack/ParserSpec.scala b/msgpack/src/test/scala/fs2/data/msgpack/ParserSpec.scala
index d163de621..2f2d858cf 100644
--- a/msgpack/src/test/scala/fs2/data/msgpack/ParserSpec.scala
+++ b/msgpack/src/test/scala/fs2/data/msgpack/ParserSpec.scala
@@ -328,7 +328,7 @@ object ParserSpec extends SimpleIOSuite {
   pureTest("Timestamp64 nanoseconds field should always be positive") {
     val nums = List(
       0xffffffffffffffffL,
-      0b1000000000000000000000000000000000000000000000000000000000000000L
+      0x8000000000000000L
     )
     forEach(nums)(x => expect(MsgpackItem.Timestamp64(x).nanoseconds > 0))
   }