diff --git a/src/arch/mips/regfile/regfile.hh b/src/arch/mips/regfile/regfile.hh
index dee883c4af..7b57b31f52 100644
--- a/src/arch/mips/regfile/regfile.hh
+++ b/src/arch/mips/regfile/regfile.hh
@@ -173,6 +173,11 @@ namespace MipsISA
         }
     };
 
+    static inline int flattenIntIndex(ThreadContext * tc, int reg)
+    {
+        return reg;
+    }
+
     void copyRegs(ThreadContext *src, ThreadContext *dest);
 
     void copyMiscRegs(ThreadContext *src, ThreadContext *dest);