diff --git a/main/src/main/scala/sbt/internal/ClassLoaders.scala b/main/src/main/scala/sbt/internal/ClassLoaders.scala
index 4bd40814c..6366343c8 100644
--- a/main/src/main/scala/sbt/internal/ClassLoaders.scala
+++ b/main/src/main/scala/sbt/internal/ClassLoaders.scala
@@ -21,6 +21,8 @@ import sbt.internal.util.Attributed.data
 import sbt.io.IO
 import sbt.librarymanagement.Configurations.{ Runtime, Test }
 
+import scala.annotation.tailrec
+
 private[sbt] object ClassLoaders {
   private[this] val interfaceLoader = classOf[sbt.testing.Framework].getClassLoader
   /*
@@ -214,9 +216,15 @@ private[sbt] object SbtMetaBuildClassLoader {
     }
   }
   def apply(libraryLoader: ClassLoader, fullLoader: ClassLoader): ClassLoader = {
+    @tailrec
+    def bootLoader(classLoader: ClassLoader): ClassLoader = classLoader.getParent match {
+      case null                                                               => classLoader
+      case c if c.getClass.getCanonicalName == "xsbt.boot.BootFilteredLoader" => c
+      case c                                                                  => bootLoader(c)
+    }
     val interfaceFilter: URL => Boolean = _.getFile.endsWith("test-interface-1.0.jar")
     val (interfaceURL, rest) = fullLoader.urls.partition(interfaceFilter)
-    val interfaceLoader = new URLClassLoader(interfaceURL, libraryLoader.getParent) {
+    val interfaceLoader = new URLClassLoader(interfaceURL, bootLoader(libraryLoader)) {
       override def toString: String = s"SbtTestInterfaceClassLoader(${getURLs.head})"
     }
     val updatedLibraryLoader = new URLClassLoader(libraryLoader.urls, interfaceLoader) {
diff --git a/sbt/src/sbt-test/tests/test-cross/build.sbt b/sbt/src/sbt-test/tests/test-cross/build.sbt
new file mode 100644
index 000000000..dabf9b70b
--- /dev/null
+++ b/sbt/src/sbt-test/tests/test-cross/build.sbt
@@ -0,0 +1,8 @@
+val scalatest = "org.scalatest" %% "scalatest" % "3.0.5"
+
+lazy val root = (project in file("."))
+  .settings(
+    // Verifies that a different scala library version still works in test
+    scalaVersion := "2.11.12",
+    libraryDependencies += scalatest % Test
+  )
diff --git a/sbt/src/sbt-test/tests/test-cross/src/test/scala/Test.scala b/sbt/src/sbt-test/tests/test-cross/src/test/scala/Test.scala
new file mode 100644
index 000000000..8a6430745
--- /dev/null
+++ b/sbt/src/sbt-test/tests/test-cross/src/test/scala/Test.scala
@@ -0,0 +1,8 @@
+import java.io.File
+import org.scalatest.FlatSpec
+
+class Test extends FlatSpec {
+  "a test" should "pass" in {
+    assert(true)
+  }
+}
diff --git a/sbt/src/sbt-test/tests/test-cross/test b/sbt/src/sbt-test/tests/test-cross/test
new file mode 100644
index 000000000..dfffb838b
--- /dev/null
+++ b/sbt/src/sbt-test/tests/test-cross/test
@@ -0,0 +1 @@
+> test
diff --git a/scripted-sbt-redux/src/main/scala/sbt/scriptedtest/ScriptedTests.scala b/scripted-sbt-redux/src/main/scala/sbt/scriptedtest/ScriptedTests.scala
index 128e794ae..fc6dde494 100644
--- a/scripted-sbt-redux/src/main/scala/sbt/scriptedtest/ScriptedTests.scala
+++ b/scripted-sbt-redux/src/main/scala/sbt/scriptedtest/ScriptedTests.scala
@@ -255,7 +255,9 @@ final class ScriptedTests(
       case "source-dependencies/linearization"                      => LauncherBased // sbt/Package$
       case "source-dependencies/named"                              => LauncherBased // sbt/Package$
       case "source-dependencies/specialized"                        => LauncherBased // sbt/Package$
-      case _                                                        => RunFromSourceBased
+      case "tests/test-cross" =>
+        LauncherBased // the sbt metabuild classpath leaks into the test interface classloader in older versions of sbt
+      case _ => RunFromSourceBased
     }
     // sbt/Package$ means:
     //   java.lang.NoClassDefFoundError: sbt/Package$ (wrong name: sbt/package$)