diff --git a/sys/x86/cpufreq/hwpstate_intel.c b/sys/x86/cpufreq/hwpstate_intel.c
--- a/sys/x86/cpufreq/hwpstate_intel.c
+++ b/sys/x86/cpufreq/hwpstate_intel.c
@@ -507,7 +507,7 @@
 
 	SYSCTL_ADD_PROC(device_get_sysctl_ctx(dev),
 	    SYSCTL_CHILDREN(device_get_sysctl_tree(dev)), OID_AUTO,
-	    "epp", CTLTYPE_INT | CTLFLAG_RWTUN | CTLFLAG_MPSAFE, dev, 0,
+	    "epp", CTLTYPE_INT | CTLFLAG_RWTUN | CTLFLAG_NEEDGIANT, dev, 0,
 	    sysctl_epp_select, "I",
 	    "Efficiency/Performance Preference "
 	    "(range from 0, most performant, through 100, most efficient)");