diff --git a/sys/dev/powermng/powernow/powernow.c b/sys/dev/powermng/powernow/powernow.c
--- a/sys/dev/powermng/powernow/powernow.c
+++ b/sys/dev/powermng/powernow/powernow.c
@@ -340,7 +340,7 @@
 }
 
 static struct sysctl_ctx_list machdep_powernow_ctx;
-static char	freqs_available[80];
+static char	freqs_available[256];
 
 static int
 powernow_init(void)