diff --git a/src/soc/intel/broadwell/igd.c b/src/soc/intel/broadwell/igd.c
index 37f3871..ecb5417 100644
--- a/src/soc/intel/broadwell/igd.c
+++ b/src/soc/intel/broadwell/igd.c
@@ -348,10 +348,10 @@
 		south_chicken2 = gtt_read(SOUTH_CHICKEN2);
 		if (conf->gpu_pch_backlight_pwm_hz > hz_limit) {
 			pwm_increment = 16;
-			south_chicken2 &= ~(1 << 5);
+			south_chicken2 |= 1 << 5;
 		} else {
 			pwm_increment = 128;
-			south_chicken2 |= 1 << 5;
+			south_chicken2 &= ~(1 << 5);
 		}
 		gtt_write(SOUTH_CHICKEN2, south_chicken2);