diff --git a/tools/core/src/main/java/org/teavm/tooling/builder/ClassLoaderFactory.java b/tools/core/src/main/java/org/teavm/tooling/builder/ClassLoaderFactory.java
deleted file mode 100644
index ac62b7d10..000000000
--- a/tools/core/src/main/java/org/teavm/tooling/builder/ClassLoaderFactory.java
+++ /dev/null
@@ -1,22 +0,0 @@
-/*
- *  Copyright 2018 Alexey Andreev.
- *
- *  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.
- */
-package org.teavm.tooling.builder;
-
-import java.net.URL;
-
-public interface ClassLoaderFactory {
-    ClassLoader create(URL[] urls, ClassLoader innerClassLoader);
-}
diff --git a/tools/core/src/main/java/org/teavm/tooling/builder/InProcessBuildStrategy.java b/tools/core/src/main/java/org/teavm/tooling/builder/InProcessBuildStrategy.java
index ff45d55b7..241109968 100644
--- a/tools/core/src/main/java/org/teavm/tooling/builder/InProcessBuildStrategy.java
+++ b/tools/core/src/main/java/org/teavm/tooling/builder/InProcessBuildStrategy.java
@@ -16,14 +16,15 @@
 package org.teavm.tooling.builder;
 
 import java.io.File;
+import java.io.IOException;
 import java.net.MalformedURLException;
 import java.net.URL;
+import java.net.URLClassLoader;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.List;
 import java.util.Properties;
-import java.util.Set;
 import java.util.stream.Collectors;
 import org.teavm.backend.wasm.render.WasmBinaryVersion;
 import org.teavm.callgraph.CallGraph;
@@ -40,7 +41,6 @@ import org.teavm.vm.TeaVMOptimizationLevel;
 import org.teavm.vm.TeaVMProgressListener;
 
 public class InProcessBuildStrategy implements BuildStrategy {
-    private final ClassLoaderFactory classLoaderFactory;
     private List<String> classPathEntries = new ArrayList<>();
     private TeaVMTargetType targetType;
     private String mainClass;
@@ -71,10 +71,6 @@ public class InProcessBuildStrategy implements BuildStrategy {
     private boolean shortFileNames;
     private boolean assertionsRemoved;
 
-    public InProcessBuildStrategy(ClassLoaderFactory classLoaderFactory) {
-        this.classLoaderFactory = classLoaderFactory;
-    }
-
     @Override
     public void init() {
         sourceFileProviders.clear();
@@ -242,7 +238,8 @@ public class InProcessBuildStrategy implements BuildStrategy {
         tool.setEntryPointName(entryPointName);
         tool.setTargetDirectory(new File(targetDirectory));
         tool.setTargetFileName(targetFileName);
-        tool.setClassLoader(buildClassLoader());
+        var classLoader = buildClassLoader();
+        tool.setClassLoader(classLoader);
         tool.setOptimizationLevel(optimizationLevel);
         tool.setFastDependencyAnalysis(fastDependencyAnalysis);
 
@@ -273,11 +270,12 @@ public class InProcessBuildStrategy implements BuildStrategy {
 
         try {
             tool.generate();
-        } catch (TeaVMToolException | RuntimeException | Error e) {
+            classLoader.close();
+        } catch (TeaVMToolException | RuntimeException | Error | IOException e) {
             throw new BuildException(e);
         }
 
-        Set<String> generatedFiles = tool.getGeneratedFiles().stream()
+        var generatedFiles = tool.getGeneratedFiles().stream()
                 .map(File::getAbsolutePath)
                 .collect(Collectors.toSet());
 
@@ -285,7 +283,7 @@ public class InProcessBuildStrategy implements BuildStrategy {
                 tool.getProblemProvider(), tool.getClasses(), tool.getUsedResources(), generatedFiles);
     }
 
-    private ClassLoader buildClassLoader() {
+    private URLClassLoader buildClassLoader() {
         URL[] urls = classPathEntries.stream().map(entry -> {
             try {
                 return new File(entry).toURI().toURL();
@@ -294,7 +292,7 @@ public class InProcessBuildStrategy implements BuildStrategy {
             }
         }).toArray(URL[]::new);
 
-        return classLoaderFactory.create(urls, InProcessBuildStrategy.class.getClassLoader());
+        return new URLClassLoader(urls, InProcessBuildStrategy.class.getClassLoader());
     }
 
     static class InProcessBuildResult implements BuildResult {
diff --git a/tools/gradle/src/main/java/org/teavm/gradle/tasks/TeaVMTask.java b/tools/gradle/src/main/java/org/teavm/gradle/tasks/TeaVMTask.java
index dd1e55fea..8596b105e 100644
--- a/tools/gradle/src/main/java/org/teavm/gradle/tasks/TeaVMTask.java
+++ b/tools/gradle/src/main/java/org/teavm/gradle/tasks/TeaVMTask.java
@@ -17,7 +17,6 @@ package org.teavm.gradle.tasks;
 
 import java.io.File;
 import java.io.IOException;
-import java.net.URLClassLoader;
 import java.rmi.NotBoundException;
 import java.rmi.registry.LocateRegistry;
 import java.util.ArrayList;
@@ -104,7 +103,7 @@ public abstract class TeaVMTask extends DefaultTask {
         if (getOutOfProcess().get()) {
             executeInSeparateProcess();
         } else {
-            executeWithBuilder(new InProcessBuildStrategy(URLClassLoader::new));
+            executeWithBuilder(new InProcessBuildStrategy());
         }
     }
 
diff --git a/tools/maven/plugin/src/main/java/org/teavm/maven/TeaVMCompileMojo.java b/tools/maven/plugin/src/main/java/org/teavm/maven/TeaVMCompileMojo.java
index d57b1a0bb..c574baf62 100644
--- a/tools/maven/plugin/src/main/java/org/teavm/maven/TeaVMCompileMojo.java
+++ b/tools/maven/plugin/src/main/java/org/teavm/maven/TeaVMCompileMojo.java
@@ -16,7 +16,6 @@
 package org.teavm.maven;
 
 import java.io.File;
-import java.net.URLClassLoader;
 import java.rmi.NotBoundException;
 import java.rmi.RemoteException;
 import java.rmi.registry.LocateRegistry;
@@ -251,7 +250,7 @@ public class TeaVMCompileMojo extends AbstractMojo {
         if (outOfProcess) {
             executeInSeparateProcess();
         } else {
-            executeWithBuilder(new InProcessBuildStrategy(URLClassLoader::new));
+            executeWithBuilder(new InProcessBuildStrategy());
         }
     }