diff --git a/src/cpu/o3/dyn_inst.hh b/src/cpu/o3/dyn_inst.hh
index 8a0ae1d56d..47dc830e0b 100644
--- a/src/cpu/o3/dyn_inst.hh
+++ b/src/cpu/o3/dyn_inst.hh
@@ -65,8 +65,6 @@ class BaseO3DynInst : public BaseDynInst<Impl>
 
     /** Binary machine instruction type. */
     typedef TheISA::MachInst MachInst;
-    /** Extended machine instruction type. */
-    typedef TheISA::ExtMachInst ExtMachInst;
     /** Register types. */
     typedef TheISA::IntReg   IntReg;
     typedef TheISA::FloatReg FloatReg;
diff --git a/src/cpu/o3/fetch.hh b/src/cpu/o3/fetch.hh
index 672fb499be..4382197f49 100644
--- a/src/cpu/o3/fetch.hh
+++ b/src/cpu/o3/fetch.hh
@@ -83,7 +83,6 @@ class DefaultFetch
 
     /** Typedefs from ISA. */
     typedef TheISA::MachInst MachInst;
-    typedef TheISA::ExtMachInst ExtMachInst;
 
     class FetchTranslation : public BaseTLB::Translation
     {