diff --git a/src/main/scala/uk/ac/soton/ecs/can/core/ControlWord.scala b/src/main/scala/uk/ac/soton/ecs/can/core/ControlWord.scala
index 8760cb18c5661aa1826c840c40f1e76eef3d7718..5a4e3da2b6ed0d499996f17e4b3f946bb1c26268 100644
--- a/src/main/scala/uk/ac/soton/ecs/can/core/ControlWord.scala
+++ b/src/main/scala/uk/ac/soton/ecs/can/core/ControlWord.scala
@@ -11,7 +11,7 @@ class ControlWord(addrWidth: Int, immWidth: Int = 8) extends Bundle {
   val relativeBranch = Bool()
   val ramReadAddress = Vec(2, UInt(addrWidth.W))
   val ramWriteAddress = UInt(addrWidth.W)
-  val fillConstant = Bool()
+  val fillConstants = Bool()
   val incrementBlockCount = Bool()
   val roundLoop = Bool()
   val addFrom = Bool()