--- linux-2.6.21-gentoo.orig/arch/i386/kernel/cpu/cpufreq/Kconfig	2007-05-14 18:18:36.000000000 -1000
+++ linux-2.6.21-gentoo/arch/i386/kernel/cpu/cpufreq/Kconfig	2007-05-16 16:00:45.000000000 -1000
@@ -82,6 +82,7 @@ config X86_POWERNOW_K8
 	tristate "AMD Opteron/Athlon64 PowerNow!"
 	select CPU_FREQ_TABLE
 	depends on EXPERIMENTAL
+	depends on ACPI_PROCESSOR
 	help
 	  This adds the CPUFreq driver for mobile AMD Opteron/Athlon64 processors.