diff --git a/okhttp-testing-support/src/main/kotlin/okhttp3/testing/PlatformRule.kt b/okhttp-testing-support/src/main/kotlin/okhttp3/testing/PlatformRule.kt
index 7b8e2a010..280072dff 100644
--- a/okhttp-testing-support/src/main/kotlin/okhttp3/testing/PlatformRule.kt
+++ b/okhttp-testing-support/src/main/kotlin/okhttp3/testing/PlatformRule.kt
@@ -284,6 +284,7 @@ open class PlatformRule @JvmOverloads constructor(
   }
 
   fun assumeJdkVersion(majorVersion: Int) {
+    assumeNotAndroid()
     assumeTrue(PlatformVersion.majorVersion == majorVersion)
   }
 
diff --git a/okhttp-tls/build.gradle b/okhttp-tls/build.gradle
index 87561dce6..037c37224 100644
--- a/okhttp-tls/build.gradle
+++ b/okhttp-tls/build.gradle
@@ -17,6 +17,7 @@ dependencies {
   compileOnly deps.animalSniffer
 
   testImplementation project(':okhttp-testing-support')
+  testImplementation project(':mockwebserver-junit5')
   testImplementation deps.junit
   testImplementation deps.assertj
 }
diff --git a/okhttp/build.gradle b/okhttp/build.gradle
index 7b6dbfc95..79560032b 100644
--- a/okhttp/build.gradle
+++ b/okhttp/build.gradle
@@ -76,7 +76,7 @@ dependencies {
   testImplementation project(':okhttp-urlconnection')
   testImplementation project(':mockwebserver')
   testImplementation project(':mockwebserver-junit4')
-  testRuntimeOnly project(':mockwebserver-junit5')
+  testImplementation project(':mockwebserver-junit5')
   testImplementation project(':mockwebserver-deprecated')
   testImplementation project(':okhttp-logging-interceptor')
   testImplementation project(':okhttp-brotli')
diff --git a/okhttp/src/test/java/okhttp3/HttpUrlTest.java b/okhttp/src/test/java/okhttp3/HttpUrlTest.java
index a68833c31..b8a6a000b 100644
--- a/okhttp/src/test/java/okhttp3/HttpUrlTest.java
+++ b/okhttp/src/test/java/okhttp3/HttpUrlTest.java
@@ -21,6 +21,7 @@ import java.util.Collection;
 import java.util.Collections;
 import okhttp3.UrlComponentEncodingTester.Component;
 import okhttp3.UrlComponentEncodingTester.Encoding;
+import okhttp3.testing.PlatformRule;
 import org.junit.Ignore;
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -33,6 +34,8 @@ import static org.junit.jupiter.api.Assertions.fail;
 
 @RunWith(Parameterized.class)
 public final class HttpUrlTest {
+  public final PlatformRule platform = new PlatformRule();
+
   @Parameterized.Parameters(name = "Use get = {0}")
   public static Collection<Object[]> parameters() {
     return asList(
@@ -1511,6 +1514,9 @@ public final class HttpUrlTest {
   }
 
   @Test public void fromJavaNetUrlUnsupportedScheme() throws Exception {
+    // java.net.MalformedURLException: unknown protocol: mailto
+    platform.assumeNotAndroid();
+
     URL javaNetUrl = new URL("mailto:user@example.com");
     assertThat(HttpUrl.get(javaNetUrl)).isNull();
   }
diff --git a/okhttp/src/test/java/okhttp3/MediaTypeTest.java b/okhttp/src/test/java/okhttp3/MediaTypeTest.java
index da4dbdb03..58e7e4e9c 100644
--- a/okhttp/src/test/java/okhttp3/MediaTypeTest.java
+++ b/okhttp/src/test/java/okhttp3/MediaTypeTest.java
@@ -18,6 +18,7 @@ package okhttp3;
 
 import java.nio.charset.StandardCharsets;
 import java.util.Collection;
+import okhttp3.internal.platform.Platform;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.junit.runners.Parameterized;
@@ -184,7 +185,12 @@ public class MediaTypeTest {
 
   @Test public void testCharsetNameIsDoubleQuotedAndSingleQuoted() throws Exception {
     MediaType mediaType = parse("text/plain;charset=\"'utf-8'\"");
-    assertThat(mediaType.charset()).isNull();
+    if (Platform.Companion.isAndroid()) {
+      // Charset.forName("'utf-8'") == UTF-8
+      assertThat(mediaType.charset().name()).isEqualTo("UTF-8");
+    } else {
+      assertThat(mediaType.charset()).isNull();
+    }
   }
 
   @Test public void testCharsetNameIsDoubleQuotedSingleQuote() throws Exception {
diff --git a/okhttp/src/test/java/okhttp3/internal/connection/RouteSelectorTest.java b/okhttp/src/test/java/okhttp3/internal/connection/RouteSelectorTest.java
index 8ba8d6fd5..aab43162d 100644
--- a/okhttp/src/test/java/okhttp3/internal/connection/RouteSelectorTest.java
+++ b/okhttp/src/test/java/okhttp3/internal/connection/RouteSelectorTest.java
@@ -41,6 +41,7 @@ import okhttp3.Protocol;
 import okhttp3.Request;
 import okhttp3.Route;
 import okhttp3.internal.http.RecordingProxySelector;
+import okhttp3.internal.platform.Platform;
 import okhttp3.testing.PlatformRule;
 import okhttp3.testing.PlatformVersion;
 import okhttp3.tls.HandshakeCertificates;
@@ -470,10 +471,13 @@ public final class RouteSelectorTest {
   @Test public void routeToString() throws Exception {
     Route route = new Route(httpAddress(), Proxy.NO_PROXY,
         InetSocketAddress.createUnresolved("host", 1234));
-    assertThat(route.toString()).isEqualTo(
-        PlatformVersion.INSTANCE.getMajorVersion() >= 14
-            ? "Route{host/<unresolved>:1234}"
-            : "Route{host:1234}");
+    String expected;
+    if (Platform.Companion.isAndroid() || PlatformVersion.INSTANCE.getMajorVersion() < 14) {
+      expected = "Route{host:1234}";
+    } else {
+      expected = "Route{host/<unresolved>:1234}";
+    }
+    assertThat(route.toString()).isEqualTo(expected);
   }
 
   private void assertRoute(Route route, Address address, Proxy proxy, InetAddress socketAddress,
diff --git a/okhttp/src/test/java/okhttp3/internal/tls/ClientAuthTest.java b/okhttp/src/test/java/okhttp3/internal/tls/ClientAuthTest.java
index fb8180eb4..01bb4b241 100644
--- a/okhttp/src/test/java/okhttp3/internal/tls/ClientAuthTest.java
+++ b/okhttp/src/test/java/okhttp3/internal/tls/ClientAuthTest.java
@@ -34,6 +34,7 @@ import javax.net.ssl.X509TrustManager;
 import javax.security.auth.x500.X500Principal;
 import mockwebserver3.MockResponse;
 import mockwebserver3.MockWebServer;
+import mockwebserver3.junit5.internal.MockWebServerExtension;
 import okhttp3.Call;
 import okhttp3.OkHttpClient;
 import okhttp3.OkHttpClientTestRule;
@@ -47,6 +48,7 @@ import okhttp3.tls.HandshakeCertificates;
 import okhttp3.tls.HeldCertificate;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
 import org.junit.jupiter.api.extension.RegisterExtension;
 
 import static java.util.Arrays.asList;
@@ -56,6 +58,7 @@ import static okhttp3.tls.internal.TlsUtil.newTrustManager;
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.junit.jupiter.api.Assertions.fail;
 
+@ExtendWith(MockWebServerExtension.class)
 public final class ClientAuthTest {
   @RegisterExtension public final PlatformRule platform = new PlatformRule();
   @RegisterExtension public final OkHttpClientTestRule clientTestRule = new OkHttpClientTestRule();
diff --git a/okhttp/src/test/java/okhttp3/internal/tls/HostnameVerifierTest.java b/okhttp/src/test/java/okhttp3/internal/tls/HostnameVerifierTest.java
index 546444df0..8359a2a2e 100644
--- a/okhttp/src/test/java/okhttp3/internal/tls/HostnameVerifierTest.java
+++ b/okhttp/src/test/java/okhttp3/internal/tls/HostnameVerifierTest.java
@@ -30,6 +30,7 @@ import javax.security.auth.x500.X500Principal;
 import okhttp3.FakeSSLSession;
 import okhttp3.OkHttpClient;
 import okhttp3.internal.Util;
+import okhttp3.internal.platform.Platform;
 import okhttp3.testing.PlatformRule;
 import okhttp3.tls.HeldCertificate;
 import okhttp3.tls.internal.TlsUtil;
@@ -189,7 +190,7 @@ public final class HostnameVerifierTest {
         + "-----END CERTIFICATE-----\n");
 
     X509Certificate peerCertificate = ((X509Certificate) session.getPeerCertificates()[0]);
-    if (platform.isConscrypt()) {
+    if (Platform.Companion.isAndroid() || platform.isConscrypt()) {
       assertThat(certificateSANs(peerCertificate)).containsExactly("bar.com");
     } else {
       assertThat(certificateSANs(peerCertificate)).containsExactly("bar.com", "������.co.jp");
@@ -382,7 +383,7 @@ public final class HostnameVerifierTest {
         + "-----END CERTIFICATE-----\n");
 
     X509Certificate peerCertificate = ((X509Certificate) session.getPeerCertificates()[0]);
-    if (platform.isConscrypt()) {
+    if (Platform.Companion.isAndroid() || platform.isConscrypt()) {
       assertThat(certificateSANs(peerCertificate)).containsExactly("*.bar.com");
     } else {
       assertThat(certificateSANs(peerCertificate)).containsExactly("*.bar.com", "*.������.co.jp");
@@ -660,7 +661,11 @@ public final class HostnameVerifierTest {
         + "-----END CERTIFICATE-----\n");
 
     X509Certificate peerCertificate = ((X509Certificate) session.getPeerCertificates()[0]);
-    assertThat(certificateSANs(peerCertificate)).containsExactly("���.com", "���.com");
+    if (Platform.Companion.isAndroid()) {
+      assertThat(certificateSANs(peerCertificate)).containsExactly();
+    } else {
+      assertThat(certificateSANs(peerCertificate)).containsExactly("���.com", "���.com");
+    }
 
     assertThat(verifier.verify("tel.com", session)).isFalse();
     assertThat(verifier.verify("k.com", session)).isFalse();