diff --git a/sys/powerpc/powerpc/cpu.c b/sys/powerpc/powerpc/cpu.c
--- a/sys/powerpc/powerpc/cpu.c
+++ b/sys/powerpc/powerpc/cpu.c
@@ -737,16 +737,18 @@
 static void
 cpu_idle_60x(sbintime_t sbt)
 {
+#ifdef AIM
 	register_t msr;
 	uint16_t vers;
+#endif
 
 	if (!powerpc_pow_enabled)
 		return;
 
+#ifdef AIM
 	msr = mfmsr();
 	vers = mfpvr() >> 16;
 
-#ifdef AIM
 	switch (vers) {
 	case IBM970:
 	case IBM970FX: