diff --git a/telephony/java/com/android/internal/telephony/PhoneBase.java b/telephony/java/com/android/internal/telephony/PhoneBase.java
index eb406b72da1c1..a2554ba5108b1 100644
--- a/telephony/java/com/android/internal/telephony/PhoneBase.java
+++ b/telephony/java/com/android/internal/telephony/PhoneBase.java
@@ -540,7 +540,7 @@ public abstract class PhoneBase extends Handler implements Phone {
     private void setPropertiesByCarrier() {
         String carrier = SystemProperties.get("ro.carrier");
 
-        if (null == carrier || 0 == carrier.length()) {
+        if (null == carrier || 0 == carrier.length() || "unknown".equals(carrier)) {
             return;
         }