diff --git a/compiler/backend/src/org/jetbrains/jet/codegen/CallableMethod.java b/compiler/backend/src/org/jetbrains/jet/codegen/CallableMethod.java
index f90b03c287b..dd7f8e3da48 100644
--- a/compiler/backend/src/org/jetbrains/jet/codegen/CallableMethod.java
+++ b/compiler/backend/src/org/jetbrains/jet/codegen/CallableMethod.java
@@ -20,7 +20,6 @@ import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 import org.jetbrains.jet.codegen.signature.JvmMethodSignature;
 import org.jetbrains.jet.lang.descriptors.CallableDescriptor;
-import org.jetbrains.jet.lang.descriptors.ClassDescriptor;
 import org.jetbrains.jet.lang.resolve.java.JvmAbi;
 import org.jetbrains.jet.lang.resolve.java.JvmClassName;
 import org.jetbrains.jet.lang.types.JetType;
@@ -43,26 +42,24 @@ public class CallableMethod implements Callable {
     private final JvmClassName defaultImplParam;
     private final JvmMethodSignature signature;
     private final int invokeOpcode;
-    private final ClassDescriptor thisClass;
-
-    private final CallableDescriptor receiverFunction;
+    @Nullable
+    private final JvmClassName thisClass;
+    @Nullable
+    private final Type receiverParameterType;
+    @Nullable
     private final Type generateCalleeType;
 
     public CallableMethod(@NotNull JvmClassName owner, @Nullable JvmClassName defaultImplOwner, @Nullable JvmClassName defaultImplParam,
             JvmMethodSignature signature, int invokeOpcode,
-            @Nullable ClassDescriptor thisClass, @Nullable CallableDescriptor receiverFunction, @Nullable Type generateCalleeType) {
+            @Nullable JvmClassName thisClass, @Nullable Type receiverParameterType, @Nullable Type generateCalleeType) {
         this.owner = owner;
         this.defaultImplOwner = defaultImplOwner;
         this.defaultImplParam = defaultImplParam;
         this.signature = signature;
         this.invokeOpcode = invokeOpcode;
         this.thisClass = thisClass;
-        this.receiverFunction = receiverFunction;
+        this.receiverParameterType = receiverParameterType;
         this.generateCalleeType = generateCalleeType;
-
-        if (receiverFunction != null && receiverFunction.getOriginal() != receiverFunction) {
-            throw new IllegalArgumentException("receiver function parameter must be original: " + receiverFunction);
-        }
     }
 
     @NotNull
@@ -87,12 +84,12 @@ public class CallableMethod implements Callable {
         return signature.getValueParameterTypes();
     }
 
-    public JetType getThisType() {
-        return thisClass.getDefaultType();
+    public JvmClassName getThisType() {
+        return thisClass;
     }
 
-    public JetType getReceiverClass() {
-        return receiverFunction.getReceiverParameter().getType();
+    public Type getReceiverClass() {
+        return receiverParameterType;
     }
 
     void invoke(InstructionAdapter v) {
@@ -126,6 +123,6 @@ public class CallableMethod implements Callable {
     }
 
     public boolean isNeedsReceiver() {
-        return receiverFunction != null;
+        return receiverParameterType != null;
     }
 }
diff --git a/compiler/backend/src/org/jetbrains/jet/codegen/ClosureCodegen.java b/compiler/backend/src/org/jetbrains/jet/codegen/ClosureCodegen.java
index 0a78318b80f..9ec30f5243e 100644
--- a/compiler/backend/src/org/jetbrains/jet/codegen/ClosureCodegen.java
+++ b/compiler/backend/src/org/jetbrains/jet/codegen/ClosureCodegen.java
@@ -88,12 +88,19 @@ public class ClosureCodegen extends ObjectOrClosureCodegen {
         return signatureWriter.makeJvmMethodSignature("invoke");
     }
 
-    public static CallableMethod asCallableMethod(FunctionDescriptor fd) {
+    public static CallableMethod asCallableMethod(FunctionDescriptor fd, @NotNull JetTypeMapper typeMapper) {
         JvmMethodSignature descriptor = erasedInvokeSignature(fd);
         JvmClassName owner = getInternalClassName(fd);
+        Type receiverParameterType;
+        if (fd.getReceiverParameter().exists()) {
+            receiverParameterType = typeMapper.mapType(fd.getOriginal().getReceiverParameter().getType(), MapTypeMode.VALUE);
+        }
+        else {
+            receiverParameterType = null;
+        }
         final CallableMethod result = new CallableMethod(
                 owner, null, null, descriptor, INVOKEVIRTUAL,
-                getInternalType(fd), fd.getReceiverParameter().exists() ? fd.getOriginal() : null, getInternalClassName(fd).getAsmType());
+                getInternalClassName(fd), receiverParameterType, getInternalClassName(fd).getAsmType());
         return result;
     }
 
diff --git a/compiler/backend/src/org/jetbrains/jet/codegen/ExpressionCodegen.java b/compiler/backend/src/org/jetbrains/jet/codegen/ExpressionCodegen.java
index a46d6e89564..fc041debc8d 100644
--- a/compiler/backend/src/org/jetbrains/jet/codegen/ExpressionCodegen.java
+++ b/compiler/backend/src/org/jetbrains/jet/codegen/ExpressionCodegen.java
@@ -1357,7 +1357,7 @@ public class ExpressionCodegen extends JetVisitor<StackValue, StackValue> {
         //}
         if (fd instanceof ExpressionAsFunctionDescriptor || (fd instanceof SimpleFunctionDescriptor && (fd.getContainingDeclaration() instanceof FunctionDescriptor || fd.getContainingDeclaration() instanceof ScriptDescriptor))) {
             SimpleFunctionDescriptor invoke = CodegenUtil.createInvoke((FunctionDescriptor) fd);
-            callableMethod = ClosureCodegen.asCallableMethod(invoke);
+            callableMethod = ClosureCodegen.asCallableMethod(invoke, typeMapper);
         }
         else if (fd instanceof FunctionDescriptor) {
             callableMethod = typeMapper.mapToCallableMethod((FunctionDescriptor) fd, superCall, OwnerKind.IMPLEMENTATION);
diff --git a/compiler/backend/src/org/jetbrains/jet/codegen/JetTypeMapper.java b/compiler/backend/src/org/jetbrains/jet/codegen/JetTypeMapper.java
index ad30f9f1da9..f7511ca3529 100644
--- a/compiler/backend/src/org/jetbrains/jet/codegen/JetTypeMapper.java
+++ b/compiler/backend/src/org/jetbrains/jet/codegen/JetTypeMapper.java
@@ -545,7 +545,7 @@ public class JetTypeMapper {
         JvmClassName ownerForDefaultImpl;
         JvmClassName ownerForDefaultParam;
         int invokeOpcode;
-        ClassDescriptor thisClass;
+        JvmClassName thisClass;
         if (functionParent instanceof NamespaceDescriptor) {
             assert !superCall;
             owner = jvmClassNameForNamespace((NamespaceDescriptor) functionParent);
@@ -595,16 +595,23 @@ public class JetTypeMapper {
                 descriptor = mapSignature(functionDescriptor, false, OwnerKind.TRAIT_IMPL);
                 owner = JvmClassName.byInternalName(owner.getInternalName() + JvmAbi.TRAIT_IMPL_SUFFIX);
             }
-            thisClass = receiver;
+            thisClass = JvmClassName.byType(mapType(receiver.getDefaultType(), MapTypeMode.VALUE));
         }
         else {
             throw new UnsupportedOperationException("unknown function parent");
         }
 
 
+        Type receiverParameterType;
+        if (functionDescriptor.getReceiverParameter().exists()) {
+            receiverParameterType = mapType(functionDescriptor.getOriginal().getReceiverParameter().getType(), MapTypeMode.VALUE);
+        }
+        else {
+            receiverParameterType = null;
+        }
         return new CallableMethod(
                 owner, ownerForDefaultImpl, ownerForDefaultParam, descriptor, invokeOpcode,
-                thisClass, functionDescriptor.getReceiverParameter().exists() ? functionDescriptor.getOriginal() : null, null);
+                thisClass, receiverParameterType, null);
     }
     
     @NotNull
diff --git a/compiler/backend/src/org/jetbrains/jet/codegen/StackValue.java b/compiler/backend/src/org/jetbrains/jet/codegen/StackValue.java
index 1bb6577c3e0..20d8827121b 100644
--- a/compiler/backend/src/org/jetbrains/jet/codegen/StackValue.java
+++ b/compiler/backend/src/org/jetbrains/jet/codegen/StackValue.java
@@ -1083,10 +1083,10 @@ public abstract class StackValue {
             if (thisObject.exists()) {
                 if(callableMethod != null) {
                     if(receiverArgument.exists()) {
-                        return codegen.typeMapper.mapType(callableMethod.getReceiverClass(), MapTypeMode.VALUE);
+                        return callableMethod.getReceiverClass();
                     }
                     else {
-                        return codegen.typeMapper.mapType(callableMethod.getThisType(), MapTypeMode.VALUE);
+                        return callableMethod.getThisType().getAsmType();
                     }
                 }
                 else {
@@ -1101,7 +1101,7 @@ public abstract class StackValue {
             else {
                 if (receiverArgument.exists()) {
                     if(callableMethod != null)
-                        return codegen.typeMapper.mapType(callableMethod.getReceiverClass(), MapTypeMode.VALUE);
+                        return callableMethod.getReceiverClass();
                     else
                         return codegen.typeMapper.mapType(descriptor.getReceiverParameter().getType(), MapTypeMode.VALUE);
                 }