fix for 2.13

1 files changed, 2 insertions, 2 deletions

diff --git a/src/main/scala/chisel3/util/experimental/decode/TruthTable.scala b/src/main/scala/chisel3/util/experimental/decode/TruthTable.scala
index 37bfec77..cde9cf14 100644
--- a/src/main/scala/chisel3/util/experimental/decode/TruthTable.scala
+++ b/src/main/scala/chisel3/util/experimental/decode/TruthTable.scala
@@ -46,9 +46,9 @@ object TruthTable {
     require(table.map(_._1.getWidth).toSet.size == 1, "input width not equal.")
     require(table.map(_._2.getWidth).toSet.size == 1, "output width not equal.")
     val outputWidth = table.map(_._2.getWidth).head
-    new TruthTable(table.toSeq.groupBy(_._1).map { case (key, values) =>
+    new TruthTable(table.toSeq.groupBy(_._1.toString).map { case (key, values) =>
       // merge same input inputs.
-      key -> BitPat(s"b${
+      values.head._1 -> BitPat(s"b${
         Seq.tabulate(outputWidth) { i =>
           val outputSet = values.map(_._2)
             .map(bpStr)