diff --git a/generators/tracegen/src/main/scala/Tile.scala b/generators/tracegen/src/main/scala/Tile.scala
index d83b5b978a..93d3c2c9fc 100644
--- a/generators/tracegen/src/main/scala/Tile.scala
+++ b/generators/tracegen/src/main/scala/Tile.scala
@@ -251,6 +251,6 @@ class BoomTraceGenTileModuleImp(outer: BoomTraceGenTile)
   status.timeout.bits := 0.U
   status.error.valid := false.B
 
-  assert(!tracegen.io.timeout, cf"TraceGen tile ${outer.tileParams.hartId.toString}: request timed out")
+  assert(!tracegen.io.timeout, s"TraceGen tile ${outer.tileParams.hartId}: request timed out")
 
 }