diff --git a/src/i830_lvds.c b/src/i830_lvds.c
index c58a7e0..b4a5103 100644
--- a/src/i830_lvds.c
+++ b/src/i830_lvds.c
@@ -234,6 +234,12 @@ i830_lvds_set_backlight_combo(xf86OutputPtr output, int level)
 #endif
     }
 
+    /*
+     * Truncate the lowest bit since in some configs it acts as a flag for
+     * max brightness.
+     */
+    level &= ~1;
+
     blc_pwm_ctl = INREG(BLC_PWM_CTL);
     blc_pwm_ctl &= ~BACKLIGHT_DUTY_CYCLE_MASK;
     OUTREG(BLC_PWM_CTL, blc_pwm_ctl | (level << BACKLIGHT_DUTY_CYCLE_SHIFT));