diff --git a/idea/src/org/jetbrains/jet/plugin/codeInsight/ImplementMethodsHandler.java b/idea/src/org/jetbrains/jet/plugin/codeInsight/ImplementMethodsHandler.java
index b72192455f0..fb1b8eb80d3 100644
--- a/idea/src/org/jetbrains/jet/plugin/codeInsight/ImplementMethodsHandler.java
+++ b/idea/src/org/jetbrains/jet/plugin/codeInsight/ImplementMethodsHandler.java
@@ -13,13 +13,11 @@ import com.intellij.psi.PsiElement;
 import com.intellij.psi.PsiFile;
 import com.intellij.psi.util.PsiTreeUtil;
 import org.jetbrains.annotations.NotNull;
-import org.jetbrains.jet.lang.descriptors.CallableMemberDescriptor;
-import org.jetbrains.jet.lang.descriptors.DeclarationDescriptor;
-import org.jetbrains.jet.lang.descriptors.FunctionDescriptor;
-import org.jetbrains.jet.lang.descriptors.MutableClassDescriptor;
+import org.jetbrains.jet.lang.descriptors.*;
 import org.jetbrains.jet.lang.psi.*;
 import org.jetbrains.jet.lang.resolve.BindingContext;
 import org.jetbrains.jet.lang.resolve.OverrideResolver;
+import org.jetbrains.jet.lang.types.JetStandardLibrary;
 import org.jetbrains.jet.lang.types.JetType;
 import org.jetbrains.jet.plugin.compiler.WholeProjectAnalyzerFacade;
 
@@ -105,9 +103,21 @@ public class ImplementMethodsHandler implements LanguageCodeInsightActionHandler
         StringBuilder bodyBuilder = new StringBuilder("override fun ");
         bodyBuilder.append(descriptor.getName());
         bodyBuilder.append("(");
+        boolean first = true;
+        for (ValueParameterDescriptor parameterDescriptor : descriptor.getValueParameters()) {
+            if (!first) {
+                bodyBuilder.append(",");
+            }
+            first = false;
+            bodyBuilder.append(parameterDescriptor.getName());
+            bodyBuilder.append(": ");
+            bodyBuilder.append(parameterDescriptor.getOutType().toString());
+        }
         bodyBuilder.append(")");
         final JetType returnType = descriptor.getReturnType();
-        bodyBuilder.append(": ").append(returnType.toString());
+        if (!returnType.equals(JetStandardLibrary.getJetStandardLibrary(project).getTuple0Type())) {
+            bodyBuilder.append(": ").append(returnType.toString());
+        }
         bodyBuilder.append("{");
         if (returnType.isNullable()) {
             bodyBuilder.append("return null");
diff --git a/idea/src/org/jetbrains/jet/plugin/formatter/JetFormattingModelBuilder.java b/idea/src/org/jetbrains/jet/plugin/formatter/JetFormattingModelBuilder.java
index 04ef828bd79..54cb3e97069 100644
--- a/idea/src/org/jetbrains/jet/plugin/formatter/JetFormattingModelBuilder.java
+++ b/idea/src/org/jetbrains/jet/plugin/formatter/JetFormattingModelBuilder.java
@@ -27,6 +27,8 @@ public class JetFormattingModelBuilder implements FormattingModelBuilder {
 
     private static SpacingBuilder createSpacingBuilder(CodeStyleSettings settings) {
         return new SpacingBuilder(settings)
+                .before(COMMA).spaceIf(settings.SPACE_BEFORE_COMMA)
+                .after(COMMA).spaceIf(settings.SPACE_AFTER_COMMA)
                 .beforeInside(BLOCK, FUN).spaceIf(settings.SPACE_BEFORE_METHOD_LBRACE)
                 .afterInside(LBRACE, BLOCK).lineBreakInCode()
                 .beforeInside(RBRACE, CLASS_BODY).lineBreakInCode()
diff --git a/idea/testData/codeInsight/overrideImplement/javaParameters/foo/Impl.kt b/idea/testData/codeInsight/overrideImplement/javaParameters/foo/Impl.kt
new file mode 100644
index 00000000000..14c331bd84c
--- /dev/null
+++ b/idea/testData/codeInsight/overrideImplement/javaParameters/foo/Impl.kt
@@ -0,0 +1,5 @@
+import foo.Intf
+
+class Impl(): Intf {
+    <caret>
+}
diff --git a/idea/testData/codeInsight/overrideImplement/javaParameters/foo/Impl.kt.after b/idea/testData/codeInsight/overrideImplement/javaParameters/foo/Impl.kt.after
new file mode 100644
index 00000000000..a20e435f471
--- /dev/null
+++ b/idea/testData/codeInsight/overrideImplement/javaParameters/foo/Impl.kt.after
@@ -0,0 +1,7 @@
+import foo.Intf
+
+class Impl(): Intf {
+
+    override fun fooBar(i: Int, s: Array<String?>?, foo: Any?) {
+    }
+}
diff --git a/idea/testData/codeInsight/overrideImplement/javaParameters/foo/Intf.java b/idea/testData/codeInsight/overrideImplement/javaParameters/foo/Intf.java
new file mode 100644
index 00000000000..04c1e8f6dfa
--- /dev/null
+++ b/idea/testData/codeInsight/overrideImplement/javaParameters/foo/Intf.java
@@ -0,0 +1,5 @@
+package foo;
+
+interface Intf {
+    void fooBar(int i, String[] s, Object foo);
+}
diff --git a/idea/tests/org/jetbrains/jet/plugin/codeInsight/OverrideImplementTest.java b/idea/tests/org/jetbrains/jet/plugin/codeInsight/OverrideImplementTest.java
index b7f6fc28298..de80e8a49a6 100644
--- a/idea/tests/org/jetbrains/jet/plugin/codeInsight/OverrideImplementTest.java
+++ b/idea/tests/org/jetbrains/jet/plugin/codeInsight/OverrideImplementTest.java
@@ -31,7 +31,15 @@ public class OverrideImplementTest extends LightCodeInsightFixtureTestCase {
     }
 
     public void testJavaInterfaceMethod() {
-        myFixture.copyDirectoryToProject("javaInterfaceMethod", "");
+        doDirectoryTest();
+    }
+
+    public void testJavaParameters() {
+        doDirectoryTest();
+    }
+
+    private void doDirectoryTest() {
+        myFixture.copyDirectoryToProject(getTestName(true), "");
         myFixture.configureFromTempProjectFile("foo/Impl.kt");
         final PsiElement elementAtCaret = myFixture.getFile().findElementAt(myFixture.getEditor().getCaretModel().getOffset());
         final JetClassOrObject classOrObject = PsiTreeUtil.getParentOfType(elementAtCaret, JetClassOrObject.class);
@@ -44,7 +52,6 @@ public class OverrideImplementTest extends LightCodeInsightFixtureTestCase {
                                                                                ImplementMethodsHandler.membersFromDescriptors(descriptors));
             }
         }.execute();
-        myFixture.checkResultByFile("javaInterfaceMethod/foo/Impl.kt.after");
-
+        myFixture.checkResultByFile(getTestName(true) + "/foo/Impl.kt.after");
     }
 }