diff --git a/core/java/android/net/NetworkAgent.java b/core/java/android/net/NetworkAgent.java
index 8df9916..80e5b91 100644
--- a/core/java/android/net/NetworkAgent.java
+++ b/core/java/android/net/NetworkAgent.java
@@ -223,6 +223,9 @@
      * Called by the bearer code when it has a new score for this network.
      */
     public void sendNetworkScore(int score) {
+        if (score < 0) {
+            throw new IllegalArgumentException("Score must be >= 0");
+        }
         queueOrSendMessage(EVENT_NETWORK_SCORE_CHANGED, new Integer(score));
     }
 
diff --git a/services/core/java/com/android/server/ConnectivityService.java b/services/core/java/com/android/server/ConnectivityService.java
index 3062a92..75090db 100644
--- a/services/core/java/com/android/server/ConnectivityService.java
+++ b/services/core/java/com/android/server/ConnectivityService.java
@@ -4746,6 +4746,11 @@
 
     private void updateNetworkScore(NetworkAgentInfo nai, int score) {
         if (DBG) log("updateNetworkScore for " + nai.name() + " to " + score);
+        if (score < 0) {
+            loge("updateNetworkScore for " + nai.name() + " got a negative score (" + score +
+                    ").  Bumping score to min of 0");
+            score = 0;
+        }
 
         nai.currentScore = score;