diff --git a/sys/dev/drm/i915/intel_dp_aux_backlight.c b/sys/dev/drm/i915/intel_dp_aux_backlight.c
@@ -111,7 +111,8 @@
 	struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
 	struct intel_dp *intel_dp = enc_to_intel_dp(&connector->encoder->base);
 	int freq, fxp, fxp_min, fxp_max, fxp_actual, f = 1;
-	u8 pn, pn_min, pn_max;
+	u8 pn_min, pn_max;
+	int pn;
 
 	/* Find desired value of (F x P)
 	 * Note that, if F x P is out of supported range, the maximum value or