diff --git a/src/arch/arm/regs/misc.cc b/src/arch/arm/regs/misc.cc
index 6f6b179e2e..8cf64d136a 100644
--- a/src/arch/arm/regs/misc.cc
+++ b/src/arch/arm/regs/misc.cc
@@ -4933,7 +4933,6 @@ ISA::initializeMiscRegMetadata()
       .allPrivileges().exceptUserMode().writes(0);
     InitReg(MISCREG_UNKNOWN);
     InitReg(MISCREG_IMPDEF_UNIMPL)
-      .unimplemented()
       .fault(EL1, faultImpdefUnimplEL1)
       .fault(EL2, faultUnimplemented)
       .fault(EL3, faultUnimplemented)