diff --git a/compiler/backend/src/org/jetbrains/jet/codegen/ClosureAnnotator.java b/compiler/backend/src/org/jetbrains/jet/codegen/ClosureAnnotator.java
index 707b824cece..ef5926695f1 100644
--- a/compiler/backend/src/org/jetbrains/jet/codegen/ClosureAnnotator.java
+++ b/compiler/backend/src/org/jetbrains/jet/codegen/ClosureAnnotator.java
@@ -42,6 +42,8 @@ public class ClosureAnnotator {
     private final Map<JetElement, JvmClassName> classNamesForAnonymousClasses = new HashMap<JetElement, JvmClassName>();
     private final Map<ClassDescriptor, JvmClassName> classNamesForClassDescriptor = new HashMap<ClassDescriptor, JvmClassName>();
     private final Map<String, Integer> anonymousSubclassesCount = new HashMap<String, Integer>();
+    private final Map<ScriptDescriptor, JvmClassName> classNameForScript = new HashMap<ScriptDescriptor, JvmClassName>();
+    private final Set<JvmClassName> scriptClassNames = new HashSet<JvmClassName>();
     private final Map<DeclarationDescriptor, ClassDescriptorImpl> classesForFunctions = new HashMap<DeclarationDescriptor, ClassDescriptorImpl>();
     private final Map<DeclarationDescriptor,ClassDescriptor> enclosing = new HashMap<DeclarationDescriptor, ClassDescriptor>();
 
@@ -86,27 +88,66 @@ public class ClosureAnnotator {
         return classDescriptor;
     }
 
+    public void registerClassNameForScript(@NotNull ScriptDescriptor scriptDescriptor, @NotNull JvmClassName className) {
+        JvmClassName oldName = classNameForScript.put(scriptDescriptor, className);
+        if (oldName != null) {
+            throw new IllegalStateException("Rewrite at key " + scriptDescriptor + " for name");
+        }
+
+        if (!scriptClassNames.add(className)) {
+            throw new IllegalStateException("More than one script has class name " + className);
+        }
+
+        ClassDescriptorImpl classDescriptor = new ClassDescriptorImpl(
+                scriptDescriptor,
+                Collections.<AnnotationDescriptor>emptyList(),
+                Name.special("<script-" + className + ">"));
+        recordName(classDescriptor, className);
+        classDescriptor.initialize(
+                false,
+                Collections.<TypeParameterDescriptor>emptyList(),
+                Collections.singletonList(JetStandardClasses.getAnyType()),
+                JetScope.EMPTY,
+                Collections.<ConstructorDescriptor>emptySet(),
+                null);
+
+        ClassDescriptorImpl oldDescriptor = classesForFunctions.put(scriptDescriptor, classDescriptor);
+        if (oldDescriptor != null) {
+            throw new IllegalStateException("Rewrite at key " + scriptDescriptor + " for class");
+        }
+    }
+
+    public void registerClassNameForScript(@NotNull JetScript jetScript, @NotNull JvmClassName className) {
+        ScriptDescriptor descriptor = bindingContext.get(BindingContext.SCRIPT, jetScript);
+        if (descriptor == null) {
+            throw new IllegalStateException("Descriptor is not found for PSI " + jetScript);
+        }
+        registerClassNameForScript(descriptor, className);
+    }
+
     @NotNull
     public ClassDescriptor classDescriptorForScrpitDescriptor(@NotNull ScriptDescriptor scriptDescriptor) {
         ClassDescriptorImpl classDescriptor = classesForFunctions.get(scriptDescriptor);
         if (classDescriptor == null) {
-            classDescriptor = new ClassDescriptorImpl(
-                    scriptDescriptor,
-                    Collections.<AnnotationDescriptor>emptyList(),
-                    Name.special("<script>"));
-            recordName(classDescriptor, JvmClassName.byInternalName("Script"));
-            classDescriptor.initialize(
-                    false,
-                    Collections.<TypeParameterDescriptor>emptyList(),
-                    Collections.singletonList(JetStandardClasses.getAnyType()),
-                    JetScope.EMPTY,
-                    Collections.<ConstructorDescriptor>emptySet(),
-                    null);
-            classesForFunctions.put(scriptDescriptor, classDescriptor);
+            throw new IllegalStateException("Class for script is not registered: " + scriptDescriptor);
         }
         return classDescriptor;
     }
 
+    @NotNull
+    public JvmClassName classNameForScriptPsi(@NotNull JetScript script) {
+        ScriptDescriptor scriptDescriptor = bindingContext.get(BindingContext.SCRIPT, script);
+        if (scriptDescriptor == null) {
+            throw new IllegalStateException("Script descriptor not found by PSI " + script);
+        }
+        return classNameForScriptDescriptor(scriptDescriptor);
+    }
+
+    @NotNull
+    public JvmClassName classNameForScriptDescriptor(@NotNull ScriptDescriptor scriptDescriptor) {
+        return classNameForClassDescriptor(classDescriptorForScrpitDescriptor(scriptDescriptor));
+    }
+
     private void mapFilesToNamespaces(Collection<JetFile> files) {
         for (JetFile file : files) {
             if (file.isScript()) {
diff --git a/compiler/backend/src/org/jetbrains/jet/codegen/ExpressionCodegen.java b/compiler/backend/src/org/jetbrains/jet/codegen/ExpressionCodegen.java
index 97f57be0065..df3170b9f40 100644
--- a/compiler/backend/src/org/jetbrains/jet/codegen/ExpressionCodegen.java
+++ b/compiler/backend/src/org/jetbrains/jet/codegen/ExpressionCodegen.java
@@ -2339,7 +2339,9 @@ public class ExpressionCodegen extends JetVisitor<StackValue, StackValue> {
         int index = -1;
 
         if (property.isScriptDeclaration()) {
-            StackValue field = StackValue.field(typeMapper.mapType(variableDescriptor.getType(), MapTypeMode.VALUE), JvmClassName.byInternalName("Script"), property.getName(), false);
+            JetScript scriptPsi = property.getScript();
+            JvmClassName scriptClassName = state.getInjector().getClosureAnnotator().classNameForScriptPsi(scriptPsi);
+            StackValue field = StackValue.field(typeMapper.mapType(variableDescriptor.getType(), MapTypeMode.VALUE), scriptClassName, property.getName(), false);
             return StackValue.none();
         }
         else {
@@ -2366,7 +2368,9 @@ public class ExpressionCodegen extends JetVisitor<StackValue, StackValue> {
         if (initializer != null) {
             if (property.isScriptDeclaration()) {
                 gen(initializer, varType);
-                v.putfield("Script", property.getName(), varType.getDescriptor());
+                JetScript scriptPsi = property.getScript();
+                JvmClassName scriptClassName = state.getInjector().getClosureAnnotator().classNameForScriptPsi(scriptPsi);
+                v.putfield(scriptClassName.getInternalName(), property.getName(), varType.getDescriptor());
             }
             else if (sharedVarType == null) {
                 gen(initializer, varType);
diff --git a/compiler/backend/src/org/jetbrains/jet/codegen/GenerationState.java b/compiler/backend/src/org/jetbrains/jet/codegen/GenerationState.java
index c2f01371176..9fa6f574c82 100644
--- a/compiler/backend/src/org/jetbrains/jet/codegen/GenerationState.java
+++ b/compiler/backend/src/org/jetbrains/jet/codegen/GenerationState.java
@@ -128,6 +128,13 @@ public class GenerationState {
     }
 
     public void compileCorrectFiles(@NotNull CompilationErrorHandler errorHandler) {
+
+        for (JetFile file : this.files) {
+            if (file.isScript()) {
+                injector.getClosureAnnotator().registerClassNameForScript(file.getScript(), ScriptCodegen.SCRIPT_DEFAULT_CLASS_NAME);
+            }
+        }
+
         MultiMap<FqName, JetFile> namespaceGrouping = new MultiMap<FqName, JetFile>();
         for (JetFile file : this.files) {
             if (file == null) throw new IllegalArgumentException("A null file given for compilation");
diff --git a/compiler/backend/src/org/jetbrains/jet/codegen/JetTypeMapper.java b/compiler/backend/src/org/jetbrains/jet/codegen/JetTypeMapper.java
index 96bda0ab3c2..a266e41e5d9 100644
--- a/compiler/backend/src/org/jetbrains/jet/codegen/JetTypeMapper.java
+++ b/compiler/backend/src/org/jetbrains/jet/codegen/JetTypeMapper.java
@@ -168,7 +168,7 @@ public class JetTypeMapper {
             return JvmClassName.byType(asmType);
         }
         else if (containingDeclaration instanceof ScriptDescriptor) {
-            return JvmClassName.byInternalName("Script");
+            return closureAnnotator.classNameForScriptDescriptor((ScriptDescriptor) containingDeclaration);
         }
         else {
             throw new UnsupportedOperationException("don't know how to generate owner for parent " + containingDeclaration);
@@ -582,7 +582,7 @@ public class JetTypeMapper {
             thisClass = null;
         }
         else if (functionParent instanceof ScriptDescriptor) {
-            thisClass = owner = ownerForDefaultParam = ownerForDefaultImpl = JvmClassName.byInternalName("Script");
+            thisClass = owner = ownerForDefaultParam = ownerForDefaultImpl = closureAnnotator.classNameForScriptDescriptor((ScriptDescriptor) functionParent);
             invokeOpcode = INVOKEVIRTUAL;
         }
         else if (functionParent instanceof ClassDescriptor) {
diff --git a/compiler/backend/src/org/jetbrains/jet/codegen/ScriptCodegen.java b/compiler/backend/src/org/jetbrains/jet/codegen/ScriptCodegen.java
index 515c2716e52..b3e7be4e382 100644
--- a/compiler/backend/src/org/jetbrains/jet/codegen/ScriptCodegen.java
+++ b/compiler/backend/src/org/jetbrains/jet/codegen/ScriptCodegen.java
@@ -26,6 +26,7 @@ import org.jetbrains.jet.lang.psi.JetScript;
 import org.jetbrains.jet.lang.psi.JetTypeParameterListOwner;
 import org.jetbrains.jet.lang.resolve.BindingContext;
 import org.jetbrains.jet.lang.resolve.java.JdkNames;
+import org.jetbrains.jet.lang.resolve.java.JvmClassName;
 import org.objectweb.asm.MethodVisitor;
 import org.objectweb.asm.Opcodes;
 import org.objectweb.asm.Type;
@@ -38,6 +39,8 @@ import javax.inject.Inject;
  */
 public class ScriptCodegen {
 
+    public static final JvmClassName SCRIPT_DEFAULT_CLASS_NAME = JvmClassName.byInternalName("Script");
+
     public static final String LAST_EXPRESSION_VALUE_FIELD_NAME = "rv";
 
     @NotNull
@@ -94,11 +97,13 @@ public class ScriptCodegen {
 
         CodegenContexts.ScriptContext context = (CodegenContexts.ScriptContext) CodegenContexts.STATIC.intoScript(scriptDescriptor, classDescriptorForScript);
 
-        ClassBuilder classBuilder = classFileFactory.newVisitor("Script.class");
+        JvmClassName className = closureAnnotator.classNameForClassDescriptor(classDescriptorForScript);
+
+        ClassBuilder classBuilder = classFileFactory.newVisitor(className.getInternalName() + ".class");
         classBuilder.defineClass(scriptDeclaration,
                 Opcodes.V1_6,
                 Opcodes.ACC_PUBLIC,
-                "Script",
+                className.getInternalName(),
                 null,
                 JdkNames.JL_OBJECT.getInternalName(),
                 new String[0]);
@@ -130,10 +135,12 @@ public class ScriptCodegen {
 
         InstructionAdapter instructionAdapter = new InstructionAdapter(mv);
 
-        instructionAdapter.load(0, Type.getObjectType("Script"));
+        JvmClassName className = closureAnnotator.classNameForClassDescriptor(classDescriptorForScript);
+
+        instructionAdapter.load(0, className.getAsmType());
         instructionAdapter.invokespecial(JdkNames.JL_OBJECT.getInternalName(), "<init>", "()V");
 
-        instructionAdapter.load(0, Type.getObjectType("Script"));
+        instructionAdapter.load(0, className.getAsmType());
 
         FrameMap frameMap = context.prepareFrame(jetTypeMapper);
 
@@ -155,7 +162,7 @@ public class ScriptCodegen {
         StackValue stackValue = new ExpressionCodegen(mv, frameMap, Type.VOID_TYPE, context, state).gen(scriptDeclaration.getBlockExpression());
         if (stackValue.type != Type.VOID_TYPE) {
             stackValue.put(stackValue.type, instructionAdapter);
-            instructionAdapter.putfield("Script", LAST_EXPRESSION_VALUE_FIELD_NAME, blockType.getDescriptor());
+            instructionAdapter.putfield(className.getInternalName(), LAST_EXPRESSION_VALUE_FIELD_NAME, blockType.getDescriptor());
         }
 
         instructionAdapter.areturn(Type.VOID_TYPE);
diff --git a/compiler/cli/src/org/jetbrains/jet/cli/jvm/compiler/KotlinToJVMBytecodeCompiler.java b/compiler/cli/src/org/jetbrains/jet/cli/jvm/compiler/KotlinToJVMBytecodeCompiler.java
index b84b1223b34..be92f662f65 100644
--- a/compiler/cli/src/org/jetbrains/jet/cli/jvm/compiler/KotlinToJVMBytecodeCompiler.java
+++ b/compiler/cli/src/org/jetbrains/jet/cli/jvm/compiler/KotlinToJVMBytecodeCompiler.java
@@ -160,7 +160,7 @@ public class KotlinToJVMBytecodeCompiler {
                                 configuration.getEnvironment().getCompilerDependencies().getRuntimeJar().toURI().toURL()
                             },
                             AllModules.class.getClassLoader()));
-                    Class<?> scriptClass = classLoader.loadClass("Script");
+                    Class<?> scriptClass = classLoader.loadClass(ScriptCodegen.SCRIPT_DEFAULT_CLASS_NAME.getFqName().getFqName());
                     scriptClass.getConstructor(String[].class).newInstance(new Object[]{ configuration.getScriptArgs().toArray(new String[0]) });
                 } catch (Exception e) {
                     throw new RuntimeException("Failed to evaluate script: " + e, e);
diff --git a/compiler/cli/src/org/jetbrains/jet/cli/jvm/repl/ReplInterpreter.java b/compiler/cli/src/org/jetbrains/jet/cli/jvm/repl/ReplInterpreter.java
index 63521577bdc..1399567cdfc 100644
--- a/compiler/cli/src/org/jetbrains/jet/cli/jvm/repl/ReplInterpreter.java
+++ b/compiler/cli/src/org/jetbrains/jet/cli/jvm/repl/ReplInterpreter.java
@@ -35,6 +35,7 @@ import org.jetbrains.jet.codegen.ClassBuilderFactories;
 import org.jetbrains.jet.codegen.CompilationErrorHandler;
 import org.jetbrains.jet.codegen.GeneratedClassLoader;
 import org.jetbrains.jet.codegen.GenerationState;
+import org.jetbrains.jet.codegen.ScriptCodegen;
 import org.jetbrains.jet.di.InjectorForTopDownAnalyzerForJvm;
 import org.jetbrains.jet.lang.descriptors.ModuleDescriptor;
 import org.jetbrains.jet.lang.psi.JetFile;
@@ -109,7 +110,7 @@ public class ReplInterpreter {
         generationState.compileCorrectFiles(CompilationErrorHandler.THROW_EXCEPTION);
 
         try {
-            Class<?> scriptClass = new GeneratedClassLoader(generationState.getFactory()).loadClass("Script");
+            Class<?> scriptClass = new GeneratedClassLoader(generationState.getFactory()).loadClass(ScriptCodegen.SCRIPT_DEFAULT_CLASS_NAME.getFqName().getFqName());
             Constructor<?> scriptInstanceConstructor = scriptClass.getConstructor(new Class<?>[0]);
             Object scriptInstance = scriptInstanceConstructor.newInstance(new Object[0]);
             Field rvField = scriptClass.getDeclaredField("rv");
diff --git a/compiler/frontend/src/org/jetbrains/jet/lang/psi/JetNamedDeclaration.java b/compiler/frontend/src/org/jetbrains/jet/lang/psi/JetNamedDeclaration.java
index 8fdf39fd1a2..8ce3419f837 100644
--- a/compiler/frontend/src/org/jetbrains/jet/lang/psi/JetNamedDeclaration.java
+++ b/compiler/frontend/src/org/jetbrains/jet/lang/psi/JetNamedDeclaration.java
@@ -22,6 +22,7 @@ import com.intellij.psi.PsiNameIdentifierOwner;
 import com.intellij.util.IncorrectOperationException;
 import org.jetbrains.annotations.NonNls;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 import org.jetbrains.jet.lang.resolve.name.Name;
 import org.jetbrains.jet.lexer.JetTokens;
 
@@ -73,6 +74,16 @@ public abstract class JetNamedDeclaration extends JetDeclaration implements PsiN
     }
 
     public boolean isScriptDeclaration() {
-        return getParent() != null && getParent().getParent() instanceof JetScript;
+        return getScript() != null;
+    }
+
+    @Nullable
+    public JetScript getScript() {
+        if (getParent() != null && getParent().getParent() instanceof JetScript) {
+            return (JetScript) getParent().getParent();
+        }
+        else {
+            return null;
+        }
     }
 }
diff --git a/compiler/tests/org/jetbrains/jet/codegen/CodegenTestCase.java b/compiler/tests/org/jetbrains/jet/codegen/CodegenTestCase.java
index 1f0de567987..9f42113c80d 100644
--- a/compiler/tests/org/jetbrains/jet/codegen/CodegenTestCase.java
+++ b/compiler/tests/org/jetbrains/jet/codegen/CodegenTestCase.java
@@ -191,7 +191,7 @@ public abstract class CodegenTestCase extends UsefulTestCase {
 
         try {
             if (myFiles.isScript()) {
-                Class<?> scriptClass = loader.loadClass("Script");
+                Class<?> scriptClass = loader.loadClass(ScriptCodegen.SCRIPT_DEFAULT_CLASS_NAME.getFqName().getFqName());
 
                 Constructor constructor = getConstructor(scriptClass, state.getScriptConstructorMethod());
                 scriptInstance = constructor.newInstance(myFiles.getScriptParameterValues().toArray());