diff --git a/build.sbt b/build.sbt
index e1dbb3e..dff73ef 100644
--- a/build.sbt
+++ b/build.sbt
@@ -19,7 +19,14 @@ lazy val `spark-stubs_24` = project
   .underModules
   .settings(
     shared,
-    libraryDependencies += Deps.sparkSql % "provided"
+    libraryDependencies += Deps.sparkSql % Provided
+  )
+
+lazy val `spark-stubs_30` = project
+  .underModules
+  .settings(
+    shared,
+    libraryDependencies += Deps.sparkSql3 % Provided
   )
 
 lazy val core = project
@@ -29,8 +36,8 @@ lazy val core = project
     name := "ammonite-spark",
     generatePropertyFile("org/apache/spark/sql/ammonitesparkinternals/ammonite-spark.properties"),
     libraryDependencies ++= Seq(
-      Deps.ammoniteReplApi % "provided",
-      Deps.sparkSql % "provided",
+      Deps.ammoniteReplApi % Provided,
+      Deps.sparkSql % Provided,
       Deps.jettyServer
     )
   )
@@ -90,6 +97,7 @@ lazy val `ammonite-spark` = project
   .aggregate(
     core,
     `spark-stubs_24`,
+    `spark-stubs_30`,
     tests
   )
   .settings(
diff --git a/modules/core/src/main/scala/org/apache/spark/sql/ammonitesparkinternals/SparkDependencies.scala b/modules/core/src/main/scala/org/apache/spark/sql/ammonitesparkinternals/SparkDependencies.scala
index b4dee11..e656d3e 100644
--- a/modules/core/src/main/scala/org/apache/spark/sql/ammonitesparkinternals/SparkDependencies.scala
+++ b/modules/core/src/main/scala/org/apache/spark/sql/ammonitesparkinternals/SparkDependencies.scala
@@ -92,10 +92,16 @@ object SparkDependencies {
   }
 
   def stubsDependency = {
-    val suffix = org.apache.spark.SPARK_VERSION.split('.').take(2) match {
+    val sv = org.apache.spark.SPARK_VERSION
+    val suffix = sv.split('.').take(2) match {
       case Array("2", n) if Try(n.toInt).toOption.exists(_ <= 3) =>
         "20"
+      case Array("2", n) if Try(n.toInt).toOption.exists(_ >= 4) =>
+        "24"
+      case Array("3", n) =>
+        "30"
       case _ =>
+        System.err.println(s"Warning: unrecognized Spark version ($sv), assuming 2.4.x")
         "24"
     }
     Dependency.of(
diff --git a/modules/spark-stubs_30/src/main/scala/org/apache/spark/repl/ExecutorClassLoader.scala b/modules/spark-stubs_30/src/main/scala/org/apache/spark/repl/ExecutorClassLoader.scala
new file mode 100644
index 0000000..5c86cc4
--- /dev/null
+++ b/modules/spark-stubs_30/src/main/scala/org/apache/spark/repl/ExecutorClassLoader.scala
@@ -0,0 +1,253 @@
+
+// Like https://github.com/apache/spark/blob/0e318acd0cc3b42e8be9cb2a53cccfdc4a0805f9/repl/src/main/scala/org/apache/spark/repl/ExecutorClassLoader.scala
+// but keeping getClassFileInputStreamFromHttpServer from former versions (so that http works without hadoop stuff)
+
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You 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.
+ */
+
+package org.apache.spark.repl
+
+import java.io.{ByteArrayOutputStream, FileNotFoundException, FilterInputStream, IOException, InputStream}
+import java.net.{HttpURLConnection, URI, URL, URLEncoder}
+import java.nio.channels.Channels
+
+import scala.util.control.NonFatal
+import org.apache.hadoop.fs.{FileSystem, Path}
+import org.apache.xbean.asm7._
+import org.apache.xbean.asm7.Opcodes._
+
+import org.apache.spark.{SparkConf, SparkEnv}
+import org.apache.spark.deploy.SparkHadoopUtil
+import org.apache.spark.internal.Logging
+import org.apache.spark.util.{ParentClassLoader, Utils}
+
+/**
+ * A ClassLoader that reads classes from a Hadoop FileSystem or Spark RPC endpoint, used to load
+ * classes defined by the interpreter when the REPL is used. Allows the user to specify if user
+ * class path should be first. This class loader delegates getting/finding resources to parent
+ * loader, which makes sense until REPL never provide resource dynamically.
+ *
+ * Note: [[ClassLoader]] will preferentially load class from parent. Only when parent is null or
+ * the load failed, that it will call the overridden `findClass` function. To avoid the potential
+ * issue caused by loading class using inappropriate class loader, we should set the parent of
+ * ClassLoader to null, so that we can fully control which class loader is used. For detailed
+ * discussion, see SPARK-18646.
+ */
+class ExecutorClassLoader(
+    conf: SparkConf,
+    env: SparkEnv,
+    classUri: String,
+    parent: ClassLoader,
+    userClassPathFirst: Boolean) extends ClassLoader(null) with Logging {
+  val uri = new URI(classUri)
+  val directory = uri.getPath
+
+  val parentLoader = new ParentClassLoader(parent)
+
+  // Allows HTTP connect and read timeouts to be controlled for testing / debugging purposes
+  private[repl] var httpUrlConnectionTimeoutMillis: Int = -1
+
+  private val fetchFn: (String) => InputStream = uri.getScheme() match {
+    case "spark" => getClassFileInputStreamFromSparkRPC
+    case "http" | "https" | "ftp" => getClassFileInputStreamFromHttpServer
+    case _ =>
+      val fileSystem = FileSystem.get(uri, SparkHadoopUtil.get.newConfiguration(conf))
+      getClassFileInputStreamFromFileSystem(fileSystem)
+  }
+
+  override def getResource(name: String): URL = {
+    parentLoader.getResource(name)
+  }
+
+  override def getResources(name: String): java.util.Enumeration[URL] = {
+    parentLoader.getResources(name)
+  }
+
+  override def findClass(name: String): Class[_] = {
+    if (userClassPathFirst) {
+      findClassLocally(name).getOrElse(parentLoader.loadClass(name))
+    } else {
+      try {
+        parentLoader.loadClass(name)
+      } catch {
+        case e: ClassNotFoundException =>
+          val classOption = findClassLocally(name)
+          classOption match {
+            case None => throw new ClassNotFoundException(name, e)
+            case Some(a) => a
+          }
+      }
+    }
+  }
+
+  private def getClassFileInputStreamFromSparkRPC(path: String): InputStream = {
+    val channel = env.rpcEnv.openChannel(s"$classUri/$path")
+    new FilterInputStream(Channels.newInputStream(channel)) {
+
+      override def read(): Int = toClassNotFound(super.read())
+
+      override def read(b: Array[Byte]): Int = toClassNotFound(super.read(b))
+
+      override def read(b: Array[Byte], offset: Int, len: Int) =
+        toClassNotFound(super.read(b, offset, len))
+
+      private def toClassNotFound(fn: => Int): Int = {
+        try {
+          fn
+        } catch {
+          case e: Exception =>
+            throw new ClassNotFoundException(path, e)
+        }
+      }
+    }
+  }
+
+  private def getClassFileInputStreamFromHttpServer(pathInDirectory: String): InputStream = {
+    val url = if (SparkEnv.get.securityManager.isAuthenticationEnabled()) {
+      val uri = new URI(classUri + "/" + urlEncode(pathInDirectory))
+      // val newuri = Utils.constructURIForAuthentication(uri, SparkEnv.get.securityManager)
+      uri.toURL
+    } else {
+      new URL(classUri + "/" + urlEncode(pathInDirectory))
+    }
+    val connection: HttpURLConnection = url.openConnection().asInstanceOf[HttpURLConnection]
+    // Set the connection timeouts (for testing purposes)
+    if (httpUrlConnectionTimeoutMillis != -1) {
+      connection.setConnectTimeout(httpUrlConnectionTimeoutMillis)
+      connection.setReadTimeout(httpUrlConnectionTimeoutMillis)
+    }
+    connection.connect()
+    try {
+      if (connection.getResponseCode != 200) {
+        // Close the error stream so that the connection is eligible for re-use
+        try {
+          connection.getErrorStream.close()
+        } catch {
+          case ioe: IOException =>
+            logError("Exception while closing error stream", ioe)
+        }
+        throw new ClassNotFoundException(s"Class file not found at URL $url")
+      } else {
+        connection.getInputStream
+      }
+    } catch {
+      case NonFatal(e) if !e.isInstanceOf[ClassNotFoundException] =>
+        connection.disconnect()
+        throw e
+    }
+  }
+
+  private def getClassFileInputStreamFromFileSystem(fileSystem: FileSystem)(
+      pathInDirectory: String): InputStream = {
+    val path = new Path(directory, pathInDirectory)
+    try {
+      fileSystem.open(path)
+    } catch {
+      case _: FileNotFoundException =>
+        throw new ClassNotFoundException(s"Class file not found at path $path")
+    }
+  }
+
+  def findClassLocally(name: String): Option[Class[_]] = {
+    val pathInDirectory = name.replace('.', '/') + ".class"
+    var inputStream: InputStream = null
+    try {
+      inputStream = fetchFn(pathInDirectory)
+      val bytes = readAndTransformClass(name, inputStream)
+      Some(defineClass(name, bytes, 0, bytes.length))
+    } catch {
+      case e: ClassNotFoundException =>
+        // We did not find the class
+        logDebug(s"Did not load class $name from REPL class server at $uri", e)
+        None
+      case e: Exception =>
+        // Something bad happened while checking if the class exists
+        logError(s"Failed to check existence of class $name on REPL class server at $uri", e)
+        None
+    } finally {
+      if (inputStream != null) {
+        try {
+          inputStream.close()
+        } catch {
+          case e: Exception =>
+            logError("Exception while closing inputStream", e)
+        }
+      }
+    }
+  }
+
+  def readAndTransformClass(name: String, in: InputStream): Array[Byte] = {
+    if (name.startsWith("line") && name.endsWith("$iw$")) {
+      // Class seems to be an interpreter "wrapper" object storing a val or var.
+      // Replace its constructor with a dummy one that does not run the
+      // initialization code placed there by the REPL. The val or var will
+      // be initialized later through reflection when it is used in a task.
+      val cr = new ClassReader(in)
+      val cw = new ClassWriter(
+        ClassWriter.COMPUTE_FRAMES + ClassWriter.COMPUTE_MAXS)
+      val cleaner = new ConstructorCleaner(name, cw)
+      cr.accept(cleaner, 0)
+      return cw.toByteArray
+    } else {
+      // Pass the class through unmodified
+      val bos = new ByteArrayOutputStream
+      val bytes = new Array[Byte](4096)
+      var done = false
+      while (!done) {
+        val num = in.read(bytes)
+        if (num >= 0) {
+          bos.write(bytes, 0, num)
+        } else {
+          done = true
+        }
+      }
+      return bos.toByteArray
+    }
+  }
+
+  /**
+   * URL-encode a string, preserving only slashes
+   */
+  def urlEncode(str: String): String = {
+    str.split('/').map(part => URLEncoder.encode(part, "UTF-8")).mkString("/")
+  }
+}
+
+class ConstructorCleaner(className: String, cv: ClassVisitor)
+extends ClassVisitor(ASM6, cv) {
+  override def visitMethod(access: Int, name: String, desc: String,
+      sig: String, exceptions: Array[String]): MethodVisitor = {
+    val mv = cv.visitMethod(access, name, desc, sig, exceptions)
+    if (name == "<init>" && (access & ACC_STATIC) == 0) {
+      // This is the constructor, time to clean it; just output some new
+      // instructions to mv that create the object and set the static MODULE$
+      // field in the class to point to it, but do nothing otherwise.
+      mv.visitCode()
+      mv.visitVarInsn(ALOAD, 0) // load this
+      mv.visitMethodInsn(INVOKESPECIAL, "java/lang/Object", "<init>", "()V", false)
+      mv.visitVarInsn(ALOAD, 0) // load this
+      // val classType = className.replace('.', '/')
+      // mv.visitFieldInsn(PUTSTATIC, classType, "MODULE$", "L" + classType + ";")
+      mv.visitInsn(RETURN)
+      mv.visitMaxs(-1, -1) // stack size and local vars will be auto-computed
+      mv.visitEnd()
+      return null
+    } else {
+      return mv
+    }
+  }
+}
diff --git a/modules/spark-stubs_30/src/main/scala/spark/repl/Main.scala b/modules/spark-stubs_30/src/main/scala/spark/repl/Main.scala
new file mode 100644
index 0000000..42e4f81
--- /dev/null
+++ b/modules/spark-stubs_30/src/main/scala/spark/repl/Main.scala
@@ -0,0 +1,6 @@
+package spark.repl
+
+object Main {
+  // May make spark ClosureCleaner a tiny bit happier
+  def interp = this
+}
diff --git a/modules/tests/src/main/scala/ammonite/spark/SparkVersions.scala b/modules/tests/src/main/scala/ammonite/spark/SparkVersions.scala
index 8a49c62..244c00f 100644
--- a/modules/tests/src/main/scala/ammonite/spark/SparkVersions.scala
+++ b/modules/tests/src/main/scala/ammonite/spark/SparkVersions.scala
@@ -5,6 +5,7 @@ object SparkVersions {
   def latest21 = "2.1.3"
   def latest22 = "2.2.2"
   def latest23 = "2.3.2"
-  def latest24 = "2.4.0"
+  def latest24 = "2.4.4"
+  def latest30 = "3.0.0-preview"
 
 }
diff --git a/modules/tests/src/test/scala/ammonite/spark/Local30Tests.scala b/modules/tests/src/test/scala/ammonite/spark/Local30Tests.scala
new file mode 100644
index 0000000..6bb73a4
--- /dev/null
+++ b/modules/tests/src/test/scala/ammonite/spark/Local30Tests.scala
@@ -0,0 +1,6 @@
+package ammonite.spark
+
+object Local30Tests extends SparkReplTests(
+  SparkVersions.latest30,
+  Local.master
+)
diff --git a/modules/tests/src/test/scala/ammonite/spark/ProgressBar30Tests.scala b/modules/tests/src/test/scala/ammonite/spark/ProgressBar30Tests.scala
new file mode 100644
index 0000000..dc1c5dc
--- /dev/null
+++ b/modules/tests/src/test/scala/ammonite/spark/ProgressBar30Tests.scala
@@ -0,0 +1,6 @@
+package ammonite.spark
+
+object ProgressBar30Tests extends ProgressBarTests(
+  SparkVersions.latest30,
+  Local.master
+)
diff --git a/modules/yarn-tests/src/test/scala/ammonite/spark/Yarn30Tests.scala b/modules/yarn-tests/src/test/scala/ammonite/spark/Yarn30Tests.scala
new file mode 100644
index 0000000..756340c
--- /dev/null
+++ b/modules/yarn-tests/src/test/scala/ammonite/spark/Yarn30Tests.scala
@@ -0,0 +1,18 @@
+package ammonite.spark
+
+object Yarn30Tests extends SparkReplTests(
+  SparkVersions.latest30,
+  "yarn",
+  "spark.executor.instances" -> "1",
+  "spark.executor.memory" -> "2g",
+  "spark.yarn.executor.memoryOverhead" -> "1g",
+  "spark.yarn.am.memory" -> "2g"
+) {
+  override def inputUrlOpt =
+    Some(
+      sys.env.getOrElse(
+        "INPUT_TXT_URL",
+        sys.error("INPUT_TXT_URL not set")
+      )
+    )
+}
diff --git a/project/Deps.scala b/project/Deps.scala
index 562ecc3..c81e82c 100644
--- a/project/Deps.scala
+++ b/project/Deps.scala
@@ -13,5 +13,6 @@ object Deps {
   def utest = "com.lihaoyi" %% "utest" % "0.7.1"
 
   def sparkSql = "org.apache.spark" %% "spark-sql" % "2.4.0"
+  def sparkSql3 = "org.apache.spark" %% "spark-sql" % "3.0.0-preview"
 
 }
diff --git a/sbt-in-docker-with-yarn-cluster.sh b/sbt-in-docker-with-yarn-cluster.sh
index be51674..1b131ea 100755
--- a/sbt-in-docker-with-yarn-cluster.sh
+++ b/sbt-in-docker-with-yarn-cluster.sh
@@ -118,15 +118,16 @@ set -e
 if [ "\$SPARK_HOME" = "" ]; then
   # prefetch stuff
 
-  export SPARK_VERSION="2.4.0"
+  for SPARK_VERSION in "2.4.4" "3.0.0-preview"; do
 
-  DEPS=()
-  DEPS+=("org.apache.spark:spark-sql_$SBV:\$SPARK_VERSION")
-  DEPS+=("org.apache.spark:spark-yarn_$SBV:\$SPARK_VERSION")
+    DEPS=()
+    DEPS+=("org.apache.spark:spark-sql_$SBV:\$SPARK_VERSION")
+    DEPS+=("org.apache.spark:spark-yarn_$SBV:\$SPARK_VERSION")
 
-  for d in "\${DEPS[@]}"; do
-    echo "Pre-fetching \$d"
-    coursier fetch $(if [ "$INTERACTIVE" = 1 ]; then echo --progress; fi) "\$d" >/dev/null
+    for d in "\${DEPS[@]}"; do
+      echo "Pre-fetching \$d"
+      coursier fetch "\$d" $(if [ "$INTERACTIVE" = 1 ]; then echo --progress; else echo "</dev/null"; fi) >/dev/null
+    done
   done
 fi