diff --git a/arch/x86/kernel/cpu/powerflags.c b/arch/x86/kernel/cpu/powerflags.c
index 5abbea297e0c..7b3fe56b1c21 100644
--- a/arch/x86/kernel/cpu/powerflags.c
+++ b/arch/x86/kernel/cpu/powerflags.c
@@ -16,5 +16,6 @@ const char *const x86_power_flags[32] = {
 	"100mhzsteps",
 	"hwpstate",
 	"",	/* tsc invariant mapped to constant_tsc */
-		/* nothing */
+	"cpb",  /* core performance boost */
+	"eff_freq_ro", /* Readonly aperf/mperf */
 };