diff --git a/api/system-current.txt b/api/system-current.txt
index b419851f85891..394b1aaf3bace 100644
--- a/api/system-current.txt
+++ b/api/system-current.txt
@@ -4288,37 +4288,6 @@ package android.net.apf {
 
 }
 
-package android.net.captiveportal {
-
-  public final class CaptivePortalProbeResult {
-    ctor public CaptivePortalProbeResult(int);
-    ctor public CaptivePortalProbeResult(int, @Nullable String, @Nullable String);
-    ctor public CaptivePortalProbeResult(int, @Nullable String, @Nullable String, @Nullable android.net.captiveportal.CaptivePortalProbeSpec);
-    method public boolean isFailed();
-    method public boolean isPartialConnectivity();
-    method public boolean isPortal();
-    method public boolean isSuccessful();
-    field @NonNull public static final android.net.captiveportal.CaptivePortalProbeResult FAILED;
-    field public static final int FAILED_CODE = 599; // 0x257
-    field public static final android.net.captiveportal.CaptivePortalProbeResult PARTIAL;
-    field public static final int PORTAL_CODE = 302; // 0x12e
-    field @NonNull public static final android.net.captiveportal.CaptivePortalProbeResult SUCCESS;
-    field public static final int SUCCESS_CODE = 204; // 0xcc
-    field @Nullable public final String detectUrl;
-    field @Nullable public final android.net.captiveportal.CaptivePortalProbeSpec probeSpec;
-    field @Nullable public final String redirectUrl;
-  }
-
-  public abstract class CaptivePortalProbeSpec {
-    method @NonNull public String getEncodedSpec();
-    method @NonNull public abstract android.net.captiveportal.CaptivePortalProbeResult getResult(int, @Nullable String);
-    method @NonNull public java.net.URL getUrl();
-    method @NonNull public static java.util.Collection<android.net.captiveportal.CaptivePortalProbeSpec> parseCaptivePortalProbeSpecs(@NonNull String);
-    method @Nullable public static android.net.captiveportal.CaptivePortalProbeSpec parseSpecOrNull(@Nullable String);
-  }
-
-}
-
 package android.net.metrics {
 
   public final class ApfProgramEvent implements android.net.metrics.IpConnectivityLog.Event {
diff --git a/api/test-current.txt b/api/test-current.txt
index cb2dc07150715..bb4d2335f7e9e 100644
--- a/api/test-current.txt
+++ b/api/test-current.txt
@@ -1371,37 +1371,6 @@ package android.net.apf {
 
 }
 
-package android.net.captiveportal {
-
-  public final class CaptivePortalProbeResult {
-    ctor public CaptivePortalProbeResult(int);
-    ctor public CaptivePortalProbeResult(int, @Nullable String, @Nullable String);
-    ctor public CaptivePortalProbeResult(int, @Nullable String, @Nullable String, @Nullable android.net.captiveportal.CaptivePortalProbeSpec);
-    method public boolean isFailed();
-    method public boolean isPartialConnectivity();
-    method public boolean isPortal();
-    method public boolean isSuccessful();
-    field @NonNull public static final android.net.captiveportal.CaptivePortalProbeResult FAILED;
-    field public static final int FAILED_CODE = 599; // 0x257
-    field public static final android.net.captiveportal.CaptivePortalProbeResult PARTIAL;
-    field public static final int PORTAL_CODE = 302; // 0x12e
-    field @NonNull public static final android.net.captiveportal.CaptivePortalProbeResult SUCCESS;
-    field public static final int SUCCESS_CODE = 204; // 0xcc
-    field @Nullable public final String detectUrl;
-    field @Nullable public final android.net.captiveportal.CaptivePortalProbeSpec probeSpec;
-    field @Nullable public final String redirectUrl;
-  }
-
-  public abstract class CaptivePortalProbeSpec {
-    method @NonNull public String getEncodedSpec();
-    method @NonNull public abstract android.net.captiveportal.CaptivePortalProbeResult getResult(int, @Nullable String);
-    method @NonNull public java.net.URL getUrl();
-    method @NonNull public static java.util.Collection<android.net.captiveportal.CaptivePortalProbeSpec> parseCaptivePortalProbeSpecs(@NonNull String);
-    method @Nullable public static android.net.captiveportal.CaptivePortalProbeSpec parseSpecOrNull(@Nullable String);
-  }
-
-}
-
 package android.net.metrics {
 
   public final class ApfProgramEvent implements android.net.metrics.IpConnectivityLog.Event {
diff --git a/packages/CaptivePortalLogin/Android.bp b/packages/CaptivePortalLogin/Android.bp
index bc614e9fc14cc..a345091aa71ec 100644
--- a/packages/CaptivePortalLogin/Android.bp
+++ b/packages/CaptivePortalLogin/Android.bp
@@ -23,6 +23,7 @@ android_app {
     static_libs: [
         "androidx.legacy_legacy-support-v4",
         "metrics-constants-protos",
+        "captiveportal-lib",
     ],
     manifest: "AndroidManifest.xml",
 }
diff --git a/packages/NetworkStack/Android.bp b/packages/NetworkStack/Android.bp
index d56f97f55f7eb..57a3db586c539 100644
--- a/packages/NetworkStack/Android.bp
+++ b/packages/NetworkStack/Android.bp
@@ -14,6 +14,15 @@
 // limitations under the License.
 //
 
+java_library {
+    name: "captiveportal-lib",
+    srcs: ["common/**/*.java"],
+    libs: [
+        "androidx.annotation_annotation",
+    ],
+    sdk_version: "system_current",
+}
+
 java_defaults {
     name: "NetworkStackCommon",
     sdk_version: "system_current",
@@ -35,6 +44,7 @@ android_library {
         "networkstack-aidl-interfaces-java",
         "datastallprotosnano",
         "networkstackprotosnano",
+        "captiveportal-lib",
     ],
     manifest: "AndroidManifestBase.xml",
 }
diff --git a/core/java/android/net/captiveportal/CaptivePortalProbeResult.java b/packages/NetworkStack/common/CaptivePortalProbeResult.java
similarity index 95%
rename from core/java/android/net/captiveportal/CaptivePortalProbeResult.java
rename to packages/NetworkStack/common/CaptivePortalProbeResult.java
index a1d3de248a96b..48cd48b30085b 100644
--- a/core/java/android/net/captiveportal/CaptivePortalProbeResult.java
+++ b/packages/NetworkStack/common/CaptivePortalProbeResult.java
@@ -16,17 +16,13 @@
 
 package android.net.captiveportal;
 
-import android.annotation.NonNull;
-import android.annotation.Nullable;
-import android.annotation.SystemApi;
-import android.annotation.TestApi;
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
 
 /**
  * Result of calling isCaptivePortal().
  * @hide
  */
-@SystemApi
-@TestApi
 public final class CaptivePortalProbeResult {
     public static final int SUCCESS_CODE = 204;
     public static final int FAILED_CODE = 599;
diff --git a/core/java/android/net/captiveportal/CaptivePortalProbeSpec.java b/packages/NetworkStack/common/CaptivePortalProbeSpec.java
similarity index 95%
rename from core/java/android/net/captiveportal/CaptivePortalProbeSpec.java
rename to packages/NetworkStack/common/CaptivePortalProbeSpec.java
index b354607b88566..bf983a50ab512 100644
--- a/core/java/android/net/captiveportal/CaptivePortalProbeSpec.java
+++ b/packages/NetworkStack/common/CaptivePortalProbeSpec.java
@@ -19,16 +19,12 @@ package android.net.captiveportal;
 import static android.net.captiveportal.CaptivePortalProbeResult.PORTAL_CODE;
 import static android.net.captiveportal.CaptivePortalProbeResult.SUCCESS_CODE;
 
-import static com.android.internal.util.Preconditions.checkNotNull;
-
-import android.annotation.NonNull;
-import android.annotation.Nullable;
-import android.annotation.SystemApi;
-import android.annotation.TestApi;
 import android.text.TextUtils;
 import android.util.Log;
 
-import com.android.internal.annotations.VisibleForTesting;
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+import androidx.annotation.VisibleForTesting;
 
 import java.net.MalformedURLException;
 import java.net.URL;
@@ -40,8 +36,6 @@ import java.util.regex.Pattern;
 import java.util.regex.PatternSyntaxException;
 
 /** @hide */
-@SystemApi
-@TestApi
 public abstract class CaptivePortalProbeSpec {
     private static final String TAG = CaptivePortalProbeSpec.class.getSimpleName();
     private static final String REGEX_SEPARATOR = "@@/@@";
@@ -192,4 +186,10 @@ public abstract class CaptivePortalProbeSpec {
         // No value is a match ("no location header" passes the location rule for non-redirects)
         return pattern == null || TextUtils.isEmpty(value) || pattern.matcher(value).matches();
     }
+
+    // Throws NullPointerException if the input is null.
+    private static <T> T checkNotNull(T object) {
+        if (object == null) throw new NullPointerException();
+        return object;
+    }
 }
diff --git a/tests/net/java/android/net/captiveportal/CaptivePortalProbeSpecTest.java b/packages/NetworkStack/tests/src/android/net/captiveportal/CaptivePortalProbeSpecTest.java
similarity index 100%
rename from tests/net/java/android/net/captiveportal/CaptivePortalProbeSpecTest.java
rename to packages/NetworkStack/tests/src/android/net/captiveportal/CaptivePortalProbeSpecTest.java