diff --git a/teavm-jso/src/main/java/org/teavm/jso/JS.java b/teavm-jso/src/main/java/org/teavm/jso/JS.java
index 84f97f8f1..24bce4e8a 100644
--- a/teavm-jso/src/main/java/org/teavm/jso/JS.java
+++ b/teavm-jso/src/main/java/org/teavm/jso/JS.java
@@ -17,7 +17,6 @@ package org.teavm.jso;
 
 import java.util.Iterator;
 import org.teavm.dependency.PluggableDependency;
-import org.teavm.javascript.ni.GeneratedBy;
 import org.teavm.javascript.ni.InjectedBy;
 
 /**
@@ -54,7 +53,7 @@ public final class JS {
     @InjectedBy(JSNativeGenerator.class)
     public static native JSObject getGlobal();
 
-    @GeneratedBy(JSNativeGenerator.class)
+    @InjectedBy(JSNativeGenerator.class)
     public static native JSObject wrap(String str);
 
     @InjectedBy(JSNativeGenerator.class)
@@ -116,7 +115,7 @@ public final class JS {
     @InjectedBy(JSNativeGenerator.class)
     public static native double unwrapDouble(JSObject obj);
 
-    @GeneratedBy(JSNativeGenerator.class)
+    @InjectedBy(JSNativeGenerator.class)
     @PluggableDependency(JSNativeGenerator.class)
     public static native String unwrapString(JSObject obj);
 
diff --git a/teavm-jso/src/main/java/org/teavm/jso/JSNativeGenerator.java b/teavm-jso/src/main/java/org/teavm/jso/JSNativeGenerator.java
index 13616723f..2e049a44c 100644
--- a/teavm-jso/src/main/java/org/teavm/jso/JSNativeGenerator.java
+++ b/teavm-jso/src/main/java/org/teavm/jso/JSNativeGenerator.java
@@ -21,12 +21,9 @@ import org.teavm.dependency.*;
 import org.teavm.javascript.ast.ConstantExpr;
 import org.teavm.javascript.ast.Expr;
 import org.teavm.javascript.ast.InvocationExpr;
-import org.teavm.javascript.ni.Generator;
-import org.teavm.javascript.ni.GeneratorContext;
 import org.teavm.javascript.ni.Injector;
 import org.teavm.javascript.ni.InjectorContext;
 import org.teavm.model.ClassReader;
-import org.teavm.model.FieldReference;
 import org.teavm.model.MethodReader;
 import org.teavm.model.MethodReference;
 
@@ -34,18 +31,7 @@ import org.teavm.model.MethodReference;
  *
  * @author Alexey Andreev
  */
-public class JSNativeGenerator implements Generator, Injector, DependencyPlugin {
-    @Override
-    public void generate(GeneratorContext context, SourceWriter writer, MethodReference methodRef)
-            throws IOException {
-        if (methodRef.getName().equals("wrap")) {
-            generateWrapString(context, writer);
-        } else if (methodRef.getName().equals("unwrapString")) {
-            writer.append("return $rt_str(").append(context.getParameterName(1)).append(");")
-                    .softNewLine();
-        }
-    }
-
+public class JSNativeGenerator implements Injector, DependencyPlugin {
     @Override
     public void generate(InjectorContext context, MethodReference methodRef) throws IOException {
         SourceWriter writer = context.getWriter();
@@ -101,11 +87,22 @@ public class JSNativeGenerator implements Generator, Injector, DependencyPlugin
                 writer.append("))");
                 break;
             case "wrap":
-                context.writeExpr(context.getArgument(0));
+                if (methodRef.getDescriptor().parameterType(0).isObject("java.lang.String")) {
+                    writer.append("$rt_ustr(");
+                    context.writeExpr(context.getArgument(0));
+                    writer.append(")");
+                } else {
+                    context.writeExpr(context.getArgument(0));
+                }
                 break;
             case "function":
                 generateFunction(context);
                 break;
+            case "unwrapString":
+                writer.append("$rt_str(");
+                context.writeExpr(context.getArgument(0));
+                writer.append(")");
+                break;
             default:
                 if (methodRef.getName().startsWith("unwrap")) {
                     context.writeExpr(context.getArgument(0));
@@ -146,26 +143,15 @@ public class JSNativeGenerator implements Generator, Injector, DependencyPlugin
         }
     }
 
-    private void generateWrapString(GeneratorContext context, SourceWriter writer) throws IOException {
-        FieldReference charsField = new FieldReference("java.lang.String", "characters");
-        writer.append("var result = \"\";").softNewLine();
-        writer.append("var data = ").append(context.getParameterName(1)).append('.')
-                .appendField(charsField).append(".data;").softNewLine();
-        writer.append("for (var i = 0; i < data.length; i = (i + 1) | 0) {").indent().softNewLine();
-        writer.append("result += String.fromCharCode(data[i]);").softNewLine();
-        writer.outdent().append("}").softNewLine();
-        writer.append("return result;").softNewLine();
-    }
-
     private void generateFunction(InjectorContext context) throws IOException {
         SourceWriter writer = context.getWriter();
-        writer.append("(function($instance, $property) { return function()").ws().append("{").indent().softNewLine();
-        writer.append("return $property.apply($instance, arguments);").softNewLine();
+        writer.append("(function($instance,").ws().append("$property)").ws().append("{").ws()
+                .append("return function()").ws().append("{").indent().softNewLine();
+        writer.append("return $instance[$property].apply($instance,").ws().append("arguments);").softNewLine();
         writer.outdent().append("};})(");
         context.writeExpr(context.getArgument(0));
-        writer.append(", ");
-        context.writeExpr(context.getArgument(0));
-        renderProperty(context.getArgument(1), context);
+        writer.append(",").ws();
+        context.writeExpr(context.getArgument(1));
         writer.append(")");
     }
 
diff --git a/teavm-jso/src/main/java/org/teavm/jso/plugin/JavascriptNativeProcessor.java b/teavm-jso/src/main/java/org/teavm/jso/plugin/JavascriptNativeProcessor.java
index 8751110e7..d41f03e60 100644
--- a/teavm-jso/src/main/java/org/teavm/jso/plugin/JavascriptNativeProcessor.java
+++ b/teavm-jso/src/main/java/org/teavm/jso/plugin/JavascriptNativeProcessor.java
@@ -187,8 +187,7 @@ class JavascriptNativeProcessor {
         Variable nameVar = addStringWrap(addString(propertyName));
         InvokeInstruction insn = new InvokeInstruction();
         insn.setType(InvocationType.SPECIAL);
-        insn.setMethod(new MethodReference(JS.class.getName(), "get", ValueType.object(JSObject.class.getName()),
-                ValueType.object(JSObject.class.getName()), ValueType.object(JSObject.class.getName())));
+        insn.setMethod(new MethodReference(JS.class, "get", JSObject.class, JSObject.class, JSObject.class));
         insn.setReceiver(receiver);
         insn.getArguments().add(instance);
         insn.getArguments().add(nameVar);
@@ -199,9 +198,8 @@ class JavascriptNativeProcessor {
         Variable nameVar = addStringWrap(addString(propertyName));
         InvokeInstruction insn = new InvokeInstruction();
         insn.setType(InvocationType.SPECIAL);
-        insn.setMethod(new MethodReference(JS.class.getName(), "set",
-                ValueType.object(JSObject.class.getName()), ValueType.object(JSObject.class.getName()),
-                ValueType.object(JSObject.class.getName()), ValueType.VOID));
+        insn.setMethod(new MethodReference(JS.class, "set", JSObject.class, JSObject.class,
+                JSObject.class, void.class));
         insn.getArguments().add(instance);
         insn.getArguments().add(nameVar);
         insn.getArguments().add(value);
@@ -211,8 +209,7 @@ class JavascriptNativeProcessor {
     private void addIndexerGet(Variable array, Variable index, Variable receiver) {
         InvokeInstruction insn = new InvokeInstruction();
         insn.setType(InvocationType.SPECIAL);
-        insn.setMethod(new MethodReference(JS.class.getName(), "get", ValueType.object(JSObject.class.getName()),
-                ValueType.object(JSObject.class.getName()), ValueType.object(JSObject.class.getName())));
+        insn.setMethod(new MethodReference(JS.class, "get", JSObject.class, JSObject.class, JSObject.class));
         insn.setReceiver(receiver);
         insn.getArguments().add(array);
         insn.getArguments().add(index);
@@ -222,9 +219,8 @@ class JavascriptNativeProcessor {
     private void addIndexerSet(Variable array, Variable index, Variable value) {
         InvokeInstruction insn = new InvokeInstruction();
         insn.setType(InvocationType.SPECIAL);
-        insn.setMethod(new MethodReference(JS.class.getName(), "set",
-                ValueType.object(JSObject.class.getName()), ValueType.object(JSObject.class.getName()),
-                ValueType.object(JSObject.class.getName()), ValueType.VOID));
+        insn.setMethod(new MethodReference(JS.class, "set", JSObject.class, JSObject.class,
+                JSObject.class, void.class));
         insn.getArguments().add(array);
         insn.getArguments().add(index);
         insn.getArguments().add(value);
@@ -322,9 +318,7 @@ class JavascriptNativeProcessor {
         Variable nameVar = addStringWrap(addString(name));
         InvokeInstruction insn = new InvokeInstruction();
         insn.setType(InvocationType.SPECIAL);
-        insn.setMethod(new MethodReference(JS.class.getName(), "function",
-                ValueType.object(JSObject.class.getName()), ValueType.object(JSObject.class.getName()),
-                ValueType.object(JSObject.class.getName())));
+        insn.setMethod(new MethodReference(JS.class, "function", JSObject.class, JSObject.class, JSObject.class));
         insn.setReceiver(functor);
         insn.getArguments().add(var);
         insn.getArguments().add(nameVar);
diff --git a/teavm-samples/teavm-samples-hello/pom.xml b/teavm-samples/teavm-samples-hello/pom.xml
index eda584209..d1183f430 100644
--- a/teavm-samples/teavm-samples-hello/pom.xml
+++ b/teavm-samples/teavm-samples-hello/pom.xml
@@ -81,7 +81,7 @@
               <targetDirectory>${project.build.directory}/generated/js/teavm</targetDirectory>
               <mainClass>org.teavm.samples.hello.Client</mainClass>
               <runtime>SEPARATE</runtime>
-              <minifying>true</minifying>
+              <minifying>false</minifying>
               <debugInformationGenerated>true</debugInformationGenerated>
               <sourceMapsGenerated>true</sourceMapsGenerated>
               <sourceFilesCopied>true</sourceFilesCopied>