diff --git a/generators/chipyard/src/main/scala/config/fragments/PeripheralFragments.scala b/generators/chipyard/src/main/scala/config/fragments/PeripheralFragments.scala
index 27f52c4d..290e3dfe 100644
--- a/generators/chipyard/src/main/scala/config/fragments/PeripheralFragments.scala
+++ b/generators/chipyard/src/main/scala/config/fragments/PeripheralFragments.scala
@@ -29,13 +29,13 @@ import chipyard.{ExtTLMem}
   * @param hang the power-on reset vector, i.e. the program counter will be set to this value on reset
   * @param contentFileName the path to the BootROM image
   */
-class WithBootROM(address: BigInt = 0x10000, size: Int = 0x10000, hang: BigInt = 0x10040, contentFileName: String = s"${site(TargetDirKey)}/bootrom.rv${site(XLen)}.img") extends Config((site, here, up) => {
+class WithBootROM(address: BigInt = 0x10000, size: Int = 0x10000, hang: BigInt = 0x10040) extends Config((site, here, up) => {
   case BootROMLocated(x) => up(BootROMLocated(x), site)
       .map(_.copy(
         address = address,
         size = size,
         hang = hang,
-        contentFileName = contentFileName
+        contentFileName = s"${site(TargetDirKey)}/bootrom.rv${site(XLen)}.img"
       ))
 })