diff --git a/core/java/android/app/ActivityThread.java b/core/java/android/app/ActivityThread.java
index f453289..d9c82ea 100644
--- a/core/java/android/app/ActivityThread.java
+++ b/core/java/android/app/ActivityThread.java
@@ -1003,9 +1003,8 @@
         }
 
         public void updateHttpProxy() {
-            final ConnectivityManager cm = ConnectivityManager.from(
+            ActivityThread.updateHttpProxy(
                     getApplication() != null ? getApplication() : getSystemContext());
-            Proxy.setHttpProxySystemProperty(cm.getDefaultProxy());
         }
 
         public void processInBackground() {
@@ -6690,6 +6689,11 @@
         return thread;
     }
 
+    public static void updateHttpProxy(@NonNull Context context) {
+        final ConnectivityManager cm = ConnectivityManager.from(context);
+        Proxy.setHttpProxySystemProperty(cm.getDefaultProxy());
+    }
+
     @UnsupportedAppUsage
     public final void installSystemProviders(List<ProviderInfo> providers) {
         if (providers != null) {
diff --git a/services/core/java/com/android/server/am/ActivityManagerService.java b/services/core/java/com/android/server/am/ActivityManagerService.java
index e18f374..5ebd173 100644
--- a/services/core/java/com/android/server/am/ActivityManagerService.java
+++ b/services/core/java/com/android/server/am/ActivityManagerService.java
@@ -318,7 +318,6 @@
 import android.media.audiofx.AudioEffect;
 import android.metrics.LogMaker;
 import android.net.Proxy;
-import android.net.ProxyInfo;
 import android.net.Uri;
 import android.os.BatteryStats;
 import android.os.Binder;
@@ -2252,21 +2251,25 @@
                 }
             } break;
             case UPDATE_HTTP_PROXY_MSG: {
+                // Update the HTTP proxy for each application thread.
                 synchronized (ActivityManagerService.this) {
                     for (int i = mLruProcesses.size() - 1 ; i >= 0 ; i--) {
                         ProcessRecord r = mLruProcesses.get(i);
                         // Don't dispatch to isolated processes as they can't access
-                        // ConnectivityManager and don't have network privileges anyway.
-                        if (r.thread != null && !r.isolated) {
+                        // ConnectivityManager and don't have network privileges anyway. Exclude
+                        // system server and update it separately outside the AMS lock, to avoid
+                        // deadlock with Connectivity Service.
+                        if (r.pid != MY_PID && r.thread != null && !r.isolated) {
                             try {
                                 r.thread.updateHttpProxy();
                             } catch (RemoteException ex) {
-                                Slog.w(TAG, "Failed to update http proxy for: " +
-                                        r.info.processName);
+                                Slog.w(TAG, "Failed to update http proxy for: "
+                                        + r.info.processName);
                             }
                         }
                     }
                 }
+                ActivityThread.updateHttpProxy(mContext);
             } break;
             case PROC_START_TIMEOUT_MSG: {
                 ProcessRecord app = (ProcessRecord)msg.obj;
@@ -2607,7 +2610,7 @@
             } break;
             }
         }
-    };
+    }
 
     static final int COLLECT_PSS_BG_MSG = 1;