diff --git a/api/system-current.txt b/api/system-current.txt
index 5da2db8383e06..062df8d1bf122 100755
--- a/api/system-current.txt
+++ b/api/system-current.txt
@@ -4864,6 +4864,14 @@ package android.net {
     method @NonNull public android.net.StaticIpConfiguration.Builder setIpAddress(@Nullable android.net.LinkAddress);
   }
 
+  public final class StringNetworkSpecifier extends android.net.NetworkSpecifier implements android.os.Parcelable {
+    ctor public StringNetworkSpecifier(@NonNull String);
+    method public int describeContents();
+    method public void writeToParcel(@NonNull android.os.Parcel, int);
+    field @NonNull public static final android.os.Parcelable.Creator<android.net.StringNetworkSpecifier> CREATOR;
+    field @NonNull public final String specifier;
+  }
+
   public class TrafficStats {
     method public static void setThreadStatsTagApp();
     method public static void setThreadStatsTagBackup();
diff --git a/core/java/android/net/StringNetworkSpecifier.java b/core/java/android/net/StringNetworkSpecifier.java
index 21dee55eb0fb8..83dbc637fb65b 100644
--- a/core/java/android/net/StringNetworkSpecifier.java
+++ b/core/java/android/net/StringNetworkSpecifier.java
@@ -16,7 +16,8 @@
 
 package android.net;
 
-import android.annotation.UnsupportedAppUsage;
+import android.annotation.NonNull;
+import android.annotation.SystemApi;
 import android.os.Parcel;
 import android.os.Parcelable;
 import android.text.TextUtils;
@@ -26,18 +27,20 @@ import com.android.internal.util.Preconditions;
 import java.util.Objects;
 
 /** @hide */
+@SystemApi
 public final class StringNetworkSpecifier extends NetworkSpecifier implements Parcelable {
     /**
      * Arbitrary string used to pass (additional) information to the network factory.
      */
-    @UnsupportedAppUsage
+    @NonNull
     public final String specifier;
 
-    public StringNetworkSpecifier(String specifier) {
+    public StringNetworkSpecifier(@NonNull String specifier) {
         Preconditions.checkStringNotEmpty(specifier);
         this.specifier = specifier;
     }
 
+    /** @hide */
     @Override
     public boolean satisfiedBy(NetworkSpecifier other) {
         return equals(other);
@@ -65,11 +68,11 @@ public final class StringNetworkSpecifier extends NetworkSpecifier implements Pa
     }
 
     @Override
-    public void writeToParcel(Parcel dest, int flags) {
+    public void writeToParcel(@NonNull Parcel dest, int flags) {
         dest.writeString(specifier);
     }
 
-    public static final @android.annotation.NonNull Parcelable.Creator<StringNetworkSpecifier> CREATOR =
+    public static final @NonNull Parcelable.Creator<StringNetworkSpecifier> CREATOR =
             new Parcelable.Creator<StringNetworkSpecifier>() {
         public StringNetworkSpecifier createFromParcel(Parcel in) {
             return new StringNetworkSpecifier(in.readString());