diff --git a/classlib/src/main/java/org/teavm/classlib/java/lang/TClassLoader.java b/classlib/src/main/java/org/teavm/classlib/java/lang/TClassLoader.java
index b7b310512..be243a747 100644
--- a/classlib/src/main/java/org/teavm/classlib/java/lang/TClassLoader.java
+++ b/classlib/src/main/java/org/teavm/classlib/java/lang/TClassLoader.java
@@ -17,15 +17,12 @@ package org.teavm.classlib.java.lang;
 
 import java.io.ByteArrayInputStream;
 import java.io.InputStream;
-import org.teavm.classlib.impl.Base64;
 import org.teavm.backend.javascript.spi.InjectedBy;
+import org.teavm.classlib.impl.Base64;
+import org.teavm.jso.JSBody;
 import org.teavm.jso.JSIndexer;
 import org.teavm.jso.JSObject;
 
-/**
- *
- * @author Alexey Andreev
- */
 public abstract class TClassLoader extends TObject {
     private TClassLoader parent;
     private static TSystemClassLoader systemClassLoader = new TSystemClassLoader();
@@ -51,15 +48,19 @@ public abstract class TClassLoader extends TObject {
         if (resources == null) {
             resources = supplyResources();
         }
-        String data = resources.getResource(name);
-        return data == null ? null : new ByteArrayInputStream(Base64.decode(data));
+        JSObject data = resources.getResource(name);
+        String dataString = resourceToString(data);
+        return dataString == null ? null : new ByteArrayInputStream(Base64.decode(dataString));
     }
 
+    @JSBody(params = "resource", script = "return resource !== null && resource !== void 0 ? resource : null;")
+    private static native String resourceToString(JSObject resource);
+
     @InjectedBy(ClassLoaderNativeGenerator.class)
     private static native ResourceContainer supplyResources();
 
     interface ResourceContainer extends JSObject {
         @JSIndexer
-        String getResource(String name);
+        JSObject getResource(String name);
     }
 }
diff --git a/tests/src/test/java/org/teavm/classlib/java/lang/ClassLoaderTest.java b/tests/src/test/java/org/teavm/classlib/java/lang/ClassLoaderTest.java
index a891474fd..24c65332a 100644
--- a/tests/src/test/java/org/teavm/classlib/java/lang/ClassLoaderTest.java
+++ b/tests/src/test/java/org/teavm/classlib/java/lang/ClassLoaderTest.java
@@ -18,6 +18,7 @@ package org.teavm.classlib.java.lang;
 import static org.junit.Assert.*;
 import java.io.BufferedReader;
 import java.io.IOException;
+import java.io.InputStream;
 import java.io.InputStreamReader;
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -37,6 +38,12 @@ public class ClassLoaderTest {
         assertEquals("qwertyui", loadResource("8"));
     }
 
+    @Test
+    public void returnsNullForNonExistentResource() {
+        InputStream input = ClassLoader.getSystemClassLoader().getResourceAsStream("non-existent-resource.txt");
+        assertNull(input);
+    }
+
     private static String loadResource(String name) {
         ClassLoader classLoader = ClassLoader.getSystemClassLoader();
         try (BufferedReader reader = new BufferedReader(new InputStreamReader(classLoader.getResourceAsStream(