diff --git a/src/arch/sparc/types.hh b/src/arch/sparc/types.hh
index 15386adcaf..8bd50b7e89 100644
--- a/src/arch/sparc/types.hh
+++ b/src/arch/sparc/types.hh
@@ -59,7 +59,7 @@ namespace SparcISA
 
     typedef int RegContextVal;
 
-    typedef uint8_t RegIndex;
+    typedef uint16_t RegIndex;
 }
 
 #endif