diff --git a/src/com/android/settings/SecuritySettings.java b/src/com/android/settings/SecuritySettings.java
index ab58dd5..7ca5815 100644
--- a/src/com/android/settings/SecuritySettings.java
+++ b/src/com/android/settings/SecuritySettings.java
@@ -185,6 +185,14 @@
         if ((TelephonyManager.PHONE_TYPE_CDMA == tm.getCurrentPhoneType()) &&
                 (tm.getLteOnCdmaMode() != Phone.LTE_ON_CDMA_TRUE)) {
             root.removePreference(root.findPreference(KEY_SIM_LOCK));
+        } else {
+            // Disable SIM lock if sim card is missing or unknown
+            if ((TelephonyManager.getDefault().getSimState() ==
+                                 TelephonyManager.SIM_STATE_ABSENT) ||
+                (TelephonyManager.getDefault().getSimState() ==
+                                 TelephonyManager.SIM_STATE_UNKNOWN)) {
+                root.findPreference(KEY_SIM_LOCK).setEnabled(false);
+            }
         }
 
         // Show password