diff --git a/src/com/android/phone/MobileNetworkSettings.java b/src/com/android/phone/MobileNetworkSettings.java
index 7a795ed..dcb0520 100644
--- a/src/com/android/phone/MobileNetworkSettings.java
+++ b/src/com/android/phone/MobileNetworkSettings.java
@@ -399,6 +399,7 @@
                 updateEnhanced4gLteState();
                 updateWiFiCallState();
                 updateVideoCallState();
+                updatePreferredNetworkType();
             }
 
             /**
@@ -1107,6 +1108,7 @@
             }
 
             updateEnhanced4gLteState();
+            updatePreferredNetworkType();
             updateCallingCategory();
 
             // Enable link to CMAS app settings depending on the value in config.xml.
@@ -1162,8 +1164,6 @@
                     R.string.enhanced_4g_lte_mode_title_variant :
                     R.string.enhanced_4g_lte_mode_title;
 
-            mButtonPreferredNetworkMode.setEnabled(hasActiveSubscriptions);
-            mButtonEnabledNetworks.setEnabled(hasActiveSubscriptions);
             mButton4glte.setTitle(enhanced4glteModeTitleId);
             mLteDataServicePref.setEnabled(hasActiveSubscriptions);
             Preference ps;
@@ -1934,6 +1934,22 @@
             }
         }
 
+        private void updatePreferredNetworkType() {
+            boolean enabled = mTelephonyManager.getCallState(
+                    mSubId) == TelephonyManager.CALL_STATE_IDLE
+                    && hasActiveSubscriptions();
+            Log.i(LOG_TAG, "updatePreferredNetworkType: " + enabled);
+            // TODO: Disentangle enabled networks vs preferred network mode, it looks like
+            // both buttons are shown to the user as "Preferred network type" and the options change
+            // based on what looks like World mode.
+            if (mButtonEnabledNetworks != null) {
+                mButtonEnabledNetworks.setEnabled(enabled);
+            }
+            if (mButtonPreferredNetworkMode != null) {
+                mButtonPreferredNetworkMode.setEnabled(enabled);
+            }
+        }
+
         private void updateCallingCategory() {
             if (mCallingCategory == null) {
                 return;