diff --git a/apex/sdkextensions/Android.bp b/apex/sdkextensions/Android.bp
index f3e2018..4c5c2b2 100644
--- a/apex/sdkextensions/Android.bp
+++ b/apex/sdkextensions/Android.bp
@@ -18,13 +18,18 @@
 
 apex {
     name: "com.android.sdkext",
-    manifest: "manifest.json",
+    defaults: [ "com.android.sdkext-defaults" ],
     binaries: [ "derive_sdk" ],
+    prebuilts: [ "cur_sdkinfo" ],
+    manifest: "manifest.json",
+}
+
+apex_defaults {
+    name: "com.android.sdkext-defaults",
     java_libs: [ "framework-sdkextensions" ],
     prebuilts: [
-      "com.android.sdkext.ldconfig",
-      "cur_sdkinfo",
-      "derive_sdk.rc",
+        "com.android.sdkext.ldconfig",
+        "derive_sdk.rc",
     ],
     key: "com.android.sdkext.key",
     certificate: ":com.android.sdkext.certificate",
diff --git a/apex/sdkextensions/TEST_MAPPING b/apex/sdkextensions/TEST_MAPPING
index 91947f3..7e77623 100644
--- a/apex/sdkextensions/TEST_MAPPING
+++ b/apex/sdkextensions/TEST_MAPPING
@@ -2,6 +2,9 @@
   "presubmit": [
     {
       "name": "CtsSdkExtTestCases"
+    },
+    {
+      "name": "apiextensions_e2e_tests"
     }
   ]
 }
diff --git a/apex/sdkextensions/derive_sdk/Android.bp b/apex/sdkextensions/derive_sdk/Android.bp
index c4e3c29..cf49902 100644
--- a/apex/sdkextensions/derive_sdk/Android.bp
+++ b/apex/sdkextensions/derive_sdk/Android.bp
@@ -12,8 +12,8 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-cc_binary {
-    name: "derive_sdk",
+cc_defaults {
+    name: "derive_sdk-defaults",
     srcs: [
         "derive_sdk.cpp",
         "sdk.proto",
@@ -30,6 +30,24 @@
     ],
 }
 
+cc_binary {
+    name: "derive_sdk",
+    defaults: [ "derive_sdk-defaults" ],
+    apex_available: [ "com.android.sdkext" ],
+    visibility: [ "//frameworks/base/apex/sdkextensions" ]
+}
+
+// Work around testing using a 64-bit test suite on 32-bit test device by
+// using a prefer32 version of derive_sdk in testing.
+cc_binary {
+    name: "derive_sdk_prefer32",
+    defaults: [ "derive_sdk-defaults" ],
+    compile_multilib: "prefer32",
+    stem: "derive_sdk",
+    apex_available: [ "test_com.android.sdkext" ],
+    visibility: [ "//frameworks/base/apex/sdkextensions/testing" ]
+}
+
 prebuilt_etc {
     name: "derive_sdk.rc",
     src: "derive_sdk.rc",
diff --git a/apex/sdkextensions/framework/Android.bp b/apex/sdkextensions/framework/Android.bp
index 2845612..5504f4e 100644
--- a/apex/sdkextensions/framework/Android.bp
+++ b/apex/sdkextensions/framework/Android.bp
@@ -22,7 +22,7 @@
         "java/**/*.java",
     ],
     path: "java",
-    visibility: [ "//frameworks/base:__pkg__" ] // For the "global" stubs.
+    visibility: [ "//frameworks/base" ] // For the "global" stubs.
 }
 
 java_library {
@@ -32,7 +32,10 @@
     libs: [ "framework-annotations-lib" ],
     permitted_packages: [ "android.os.ext" ],
     installable: true,
-    visibility: [ "//frameworks/base/apex/sdkextensions:__pkg__" ],
+    visibility: [
+        "//frameworks/base/apex/sdkextensions",
+        "//frameworks/base/apex/sdkextensions/testing",
+    ],
 }
 
 droidstubs {
@@ -65,7 +68,7 @@
     srcs: [":framework-sdkextensions-droidstubs-systemapi"],
     sdk_version: "system_current",
     visibility: [
-      "//frameworks/base:__pkg__", // Framework
-      "//frameworks/base/apex/sdkextensions:__pkg__", // sdkextensions SDK
+        "//frameworks/base", // Framework
+        "//frameworks/base/apex/sdkextensions", // sdkextensions SDK
     ]
 }
diff --git a/apex/sdkextensions/testing/Android.bp b/apex/sdkextensions/testing/Android.bp
new file mode 100644
index 0000000..e6451cc
--- /dev/null
+++ b/apex/sdkextensions/testing/Android.bp
@@ -0,0 +1,46 @@
+// Copyright (C) 2019 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+apex {
+    name: "test_com.android.sdkext",
+    visibility: [ "//system/apex/tests" ],
+    defaults: ["com.android.sdkext-defaults"],
+    manifest: "test_manifest.json",
+    prebuilts: [ "sdkinfo_45" ],
+    file_contexts: ":com.android.sdkext-file_contexts",
+    installable: false, // Should never be installed on the systemimage
+    multilib: {
+        prefer32: {
+            binaries: ["derive_sdk_prefer32"],
+        },
+    },
+    // The automated test infra ends up building this apex for 64+32-bit and
+    // then installs it on a 32-bit-only device. Work around this weirdness
+    // by preferring 32-bit.
+    compile_multilib: "prefer32",
+}
+
+genrule {
+    name: "sdkinfo_45_src",
+    out: [ "sdkinfo.binarypb" ],
+    tools: [ "gen_sdkinfo" ],
+    cmd: "$(location) -v 45 -o $(out)",
+}
+
+prebuilt_etc {
+    name: "sdkinfo_45",
+    src: ":sdkinfo_45_src",
+    filename: "sdkinfo.binarypb",
+    installable: false,
+}
diff --git a/apex/sdkextensions/testing/test_manifest.json b/apex/sdkextensions/testing/test_manifest.json
new file mode 100644
index 0000000..1b4a2b0
--- /dev/null
+++ b/apex/sdkextensions/testing/test_manifest.json
@@ -0,0 +1,4 @@
+{
+  "name": "com.android.sdkext",
+  "version": 2147483647
+}