diff --git a/src/sbt-test/sbt-api-mappings/all-libraries/build.sbt b/src/sbt-test/sbt-api-mappings/all-libraries/build.sbt
index f387f3e..86c5c6d 100644
--- a/src/sbt-test/sbt-api-mappings/all-libraries/build.sbt
+++ b/src/sbt-test/sbt-api-mappings/all-libraries/build.sbt
@@ -1,25 +1,21 @@
 def assertDownloadableApiDocumentation(url: URL) = {
-  import java.net.HttpURLConnection
-  val connection = url.openConnection().asInstanceOf[HttpURLConnection]
-  try {
-    assert(
-      (200 to 399).contains(connection.getResponseCode),
-      s"Unexpected HTTP response code ${connection.getResponseCode} when fetching $url"
-    )
-  } finally {
-    connection.disconnect()
-  }
+  java.lang.System.setProperty("http.agent", "Chrome");
+  assert(IO.readLinesURL(url).nonEmpty)
 }
 
 val check = TaskKey[Unit]("check")
 
 val scalacheckModuleId = "org.scalacheck" %% "scalacheck" % "1.14.3"
 check := {
-  assertDownloadableApiDocumentation(
-    (apiMappings in Compile in doc).value(scalaInstance.value.libraryJar)
+  // The expected URL is browsable but not accessible from JRE 8's java.net.HttpURLConnection
+  val expectedScaladocUrl =
+    "https://www.scala-lang.org/api/2.13.1/"
+
+  assert(
+    (apiMappings in Compile in doc).value(scalaInstance.value.libraryJar).toString == expectedScaladocUrl
   )
-  assertDownloadableApiDocumentation(
-    (apiMappings in Test in doc).value(scalaInstance.value.libraryJar)
+  assert(
+    (apiMappings in Test in doc).value(scalaInstance.value.libraryJar).toString == expectedScaladocUrl
   )
 
   val scalacheckJarName = Artifact.artifactName(
@@ -30,7 +26,6 @@ check := {
   val Some((_, url)) =
     (apiMappings in Test in doc).value.find(_._1.getName == scalacheckJarName)
 
-  // The expected URL is browsable but not accessible from java.net.HttpURLConnection
   val expectedUrl =
     "https://javadoc.io/page/org.scalacheck/scalacheck_2.13/1.14.3/"
   assert(url.toString == expectedUrl)
diff --git a/src/test/scala/com/thoughtworks/sbtApiMappings/BootstrapApiMappingsSpec.scala b/src/test/scala/com/thoughtworks/sbtApiMappings/BootstrapApiMappingsSpec.scala
index c0d1816..38f6215 100644
--- a/src/test/scala/com/thoughtworks/sbtApiMappings/BootstrapApiMappingsSpec.scala
+++ b/src/test/scala/com/thoughtworks/sbtApiMappings/BootstrapApiMappingsSpec.scala
@@ -6,10 +6,13 @@ import org.scalatest.wordspec.AnyWordSpec
 
 class BootstrapApiMappingsSpec extends AnyWordSpec with Matchers {
   "BootstrapSbtApiMappings" should {
-    "provide a working default bootstrapJavadocURL" in {
-      val src = Source.fromURL(BootstrapApiMappings.defaultBootstrapJavadocUrl)
-      src.take(200).mkString should include("Generated by javadoc")
-      src.close()
+    "provide a working default bootstrapJavadocURL including java.lang package" in {
+      val src = Source.fromURL(raw"${BootstrapApiMappings.defaultBootstrapJavadocUrl}java/lang/package-summary.html")
+      try {
+        src.take(200).mkString should include("Generated by javadoc")
+      } finally {
+        src.close()
+      }
     }
   }
 }