diff --git a/liblight/lights.c b/liblight/lights.c
index ccfbe10..229777a 100644
--- a/liblight/lights.c
+++ b/liblight/lights.c
@@ -1,5 +1,6 @@
 /*
  * Copyright (C) 2008 The Android Open Source Project
+ * Copyright (C) 2014 The  Linux Foundation. All rights reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -115,6 +116,9 @@
 {
     int err = 0;
     int brightness = rgb_to_brightness(state);
+    if(!dev) {
+        return -1;
+    }
     pthread_mutex_lock(&g_lock);
     err = write_int(LCD_FILE, brightness);
     pthread_mutex_unlock(&g_lock);
@@ -125,12 +129,15 @@
 set_speaker_light_locked(struct light_device_t* dev,
         struct light_state_t const* state)
 {
-    int len;
-    int alpha, red, green, blue;
+    int red, green, blue;
     int blink;
     int onMS, offMS;
     unsigned int colorRGB;
 
+    if(!dev) {
+        return -1;
+    }
+
     switch (state->flashMode) {
         case LIGHT_FLASH_TIMED:
             onMS = state->flashOnMS;
@@ -217,6 +224,9 @@
         struct light_state_t const* state)
 {
     int err = 0;
+    if(!dev) {
+        return -1;
+    }
     pthread_mutex_lock(&g_lock);
     err = write_int(BUTTON_FILE, state->color & 0xFF);
     pthread_mutex_unlock(&g_lock);