diff --git a/target-ppc/cpu.h b/target-ppc/cpu.h
index 92e26c8..6a53d70 100644
--- a/target-ppc/cpu.h
+++ b/target-ppc/cpu.h
@@ -1679,6 +1679,7 @@
 #define SPR_750_TDCL          (0x3F4)
 #define SPR_40x_IAC1          (0x3F4)
 #define SPR_MMUCSR0           (0x3F4)
+#define SPR_970_HID4          (0x3F4)
 #define SPR_DABR              (0x3F5)
 #define DABR_MASK (~(target_ulong)0x7)
 #define SPR_Exxx_BUCSR        (0x3F5)