diff --git a/org.eclipse.jdt.ui.tests/ui/org/eclipse/jdt/ui/tests/quickfix/AssistQuickFixTest18.java b/org.eclipse.jdt.ui.tests/ui/org/eclipse/jdt/ui/tests/quickfix/AssistQuickFixTest18.java
index 8919cbf..4c770c1 100644
--- a/org.eclipse.jdt.ui.tests/ui/org/eclipse/jdt/ui/tests/quickfix/AssistQuickFixTest18.java
+++ b/org.eclipse.jdt.ui.tests/ui/org/eclipse/jdt/ui/tests/quickfix/AssistQuickFixTest18.java
@@ -464,6 +464,190 @@
 		assertExpectedExistInProposals(proposals, new String[] { expected1 });
 	}
 
+	public void testConvertToLambda10() throws Exception {
+		IPackageFragment pack1= fSourceFolder.createPackageFragment("test1", false, null);
+		StringBuffer buf= new StringBuffer();
+		buf.append("package test1;\n");
+		buf.append("interface I {\n");
+		buf.append("    int foo(String s);\n");
+		buf.append("}\n");
+		buf.append("\n");
+		buf.append("interface J {\n");
+		buf.append("    Integer foo(String s);\n");
+		buf.append("}\n");
+		buf.append("\n");
+		buf.append("public class X {\n");
+		buf.append("    static void goo(I i) { }\n");
+		buf.append("\n");
+		buf.append("    static void goo(J j) { }\n");
+		buf.append("\n");
+		buf.append("    public static void main(String[] args) {\n");
+		buf.append("        goo(new I() {\n");
+		buf.append("            @Override\n");
+		buf.append("            public int foo(String s) {\n");
+		buf.append("                return 0;\n");
+		buf.append("            }\n");
+		buf.append("        });\n");
+		buf.append("    }\n");
+		buf.append("}\n");
+		ICompilationUnit cu= pack1.createCompilationUnit("X.java", buf.toString(), false, null);
+
+		int offset= buf.toString().indexOf("I()");
+		AssistContext context= getCorrectionContext(cu, offset, 0);
+		assertNoErrors(context);
+		List proposals= collectAssists(context, false);
+
+		assertNumberOfProposals(proposals, 2);
+		assertCorrectLabels(proposals);
+
+		buf= new StringBuffer();
+		buf.append("package test1;\n");
+		buf.append("interface I {\n");
+		buf.append("    int foo(String s);\n");
+		buf.append("}\n");
+		buf.append("\n");
+		buf.append("interface J {\n");
+		buf.append("    Integer foo(String s);\n");
+		buf.append("}\n");
+		buf.append("\n");
+		buf.append("public class X {\n");
+		buf.append("    static void goo(I i) { }\n");
+		buf.append("\n");
+		buf.append("    static void goo(J j) { }\n");
+		buf.append("\n");
+		buf.append("    public static void main(String[] args) {\n");
+		buf.append("        goo((I) s -> 0);\n");
+		buf.append("    }\n");
+		buf.append("}\n");
+		String expected1= buf.toString();
+
+		assertExpectedExistInProposals(proposals, new String[] { expected1 });
+	}
+
+	public void testConvertToLambda11() throws Exception {
+		IPackageFragment pack1= fSourceFolder.createPackageFragment("test1", false, null);
+		StringBuffer buf= new StringBuffer();
+		buf.append("package test1;\n");
+		buf.append("interface I {\n");
+		buf.append("    int foo(String s);\n");
+		buf.append("}\n");
+		buf.append("\n");
+		buf.append("interface J {\n");
+		buf.append("    Integer foo(String s);\n");
+		buf.append("}\n");
+		buf.append("\n");
+		buf.append("public class X extends Y {\n");
+		buf.append("    static void goo(I i) { }\n");
+		buf.append("    public static void main(String[] args) {\n");
+		buf.append("        goo(new I() {\n");
+		buf.append("            @Override\n");
+		buf.append("            public int foo(String s) {\n");
+		buf.append("                return 0;\n");
+		buf.append("            }\n");
+		buf.append("        });\n");
+		buf.append("    }\n");
+		buf.append("}\n");
+		buf.append("\n");
+		buf.append("class Y {\n");
+		buf.append("    private static void goo(J j) { }    \n");
+		buf.append("}\n");
+		ICompilationUnit cu= pack1.createCompilationUnit("X.java", buf.toString(), false, null);
+
+		int offset= buf.toString().indexOf("I()");
+		AssistContext context= getCorrectionContext(cu, offset, 0);
+		assertNoErrors(context);
+		List proposals= collectAssists(context, false);
+
+		assertNumberOfProposals(proposals, 2);
+		assertCorrectLabels(proposals);
+
+		buf= new StringBuffer();
+		buf.append("package test1;\n");
+		buf.append("interface I {\n");
+		buf.append("    int foo(String s);\n");
+		buf.append("}\n");
+		buf.append("\n");
+		buf.append("interface J {\n");
+		buf.append("    Integer foo(String s);\n");
+		buf.append("}\n");
+		buf.append("\n");
+		buf.append("public class X extends Y {\n");
+		buf.append("    static void goo(I i) { }\n");
+		buf.append("    public static void main(String[] args) {\n");
+		buf.append("        goo(s -> 0);\n");
+		buf.append("    }\n");
+		buf.append("}\n");
+		buf.append("\n");
+		buf.append("class Y {\n");
+		buf.append("    private static void goo(J j) { }    \n");
+		buf.append("}\n");
+		String expected1= buf.toString();
+
+		assertExpectedExistInProposals(proposals, new String[] { expected1 });
+	}
+
+	public void testConvertToLambda12() throws Exception {
+		IPackageFragment pack1= fSourceFolder.createPackageFragment("test1", false, null);
+		StringBuffer buf= new StringBuffer();
+		buf.append("package test1;\n");
+		buf.append("interface I {\n");
+		buf.append("    int foo(String s);\n");
+		buf.append("}\n");
+		buf.append("\n");
+		buf.append("interface J {\n");
+		buf.append("    Integer foo(String s);\n");
+		buf.append("}\n");
+		buf.append("\n");
+		buf.append("public class X extends Y {\n");
+		buf.append("    static void goo(I i) { }\n");
+		buf.append("    public static void main(String[] args) {\n");
+		buf.append("        goo(new I() {\n");
+		buf.append("            @Override\n");
+		buf.append("            public int foo(String s) {\n");
+		buf.append("                return 0;\n");
+		buf.append("            }\n");
+		buf.append("        });\n");
+		buf.append("    }\n");
+		buf.append("}\n");
+		buf.append("\n");
+		buf.append("class Y {\n");
+		buf.append("    static void goo(J j) { }    \n");
+		buf.append("}\n");
+		ICompilationUnit cu= pack1.createCompilationUnit("X.java", buf.toString(), false, null);
+
+		int offset= buf.toString().indexOf("I()");
+		AssistContext context= getCorrectionContext(cu, offset, 0);
+		assertNoErrors(context);
+		List proposals= collectAssists(context, false);
+
+		assertNumberOfProposals(proposals, 2);
+		assertCorrectLabels(proposals);
+
+		buf= new StringBuffer();
+		buf.append("package test1;\n");
+		buf.append("interface I {\n");
+		buf.append("    int foo(String s);\n");
+		buf.append("}\n");
+		buf.append("\n");
+		buf.append("interface J {\n");
+		buf.append("    Integer foo(String s);\n");
+		buf.append("}\n");
+		buf.append("\n");
+		buf.append("public class X extends Y {\n");
+		buf.append("    static void goo(I i) { }\n");
+		buf.append("    public static void main(String[] args) {\n");
+		buf.append("        goo((I) s -> 0);\n");
+		buf.append("    }\n");
+		buf.append("}\n");
+		buf.append("\n");
+		buf.append("class Y {\n");
+		buf.append("    static void goo(J j) { }    \n");
+		buf.append("}\n");
+		String expected1= buf.toString();
+
+		assertExpectedExistInProposals(proposals, new String[] { expected1 });
+	}
+
 	public void testConvertToAnonymousClassCreation1() throws Exception {
 		IPackageFragment pack1= fSourceFolder.createPackageFragment("test1", false, null);
 		StringBuffer buf= new StringBuffer();
diff --git a/org.eclipse.jdt.ui/core extension/org/eclipse/jdt/internal/corext/fix/LambdaExpressionsFix.java b/org.eclipse.jdt.ui/core extension/org/eclipse/jdt/internal/corext/fix/LambdaExpressionsFix.java
index 2412b9f..968464a 100644
--- a/org.eclipse.jdt.ui/core extension/org/eclipse/jdt/internal/corext/fix/LambdaExpressionsFix.java
+++ b/org.eclipse.jdt.ui/core extension/org/eclipse/jdt/internal/corext/fix/LambdaExpressionsFix.java
@@ -27,16 +27,11 @@
 import org.eclipse.jdt.core.dom.ASTNode;
 import org.eclipse.jdt.core.dom.ASTVisitor;
 import org.eclipse.jdt.core.dom.AnonymousClassDeclaration;
-import org.eclipse.jdt.core.dom.ArrayInitializer;
-import org.eclipse.jdt.core.dom.Assignment;
 import org.eclipse.jdt.core.dom.Block;
 import org.eclipse.jdt.core.dom.BodyDeclaration;
 import org.eclipse.jdt.core.dom.CastExpression;
 import org.eclipse.jdt.core.dom.ClassInstanceCreation;
 import org.eclipse.jdt.core.dom.CompilationUnit;
-import org.eclipse.jdt.core.dom.ConditionalExpression;
-import org.eclipse.jdt.core.dom.ConstructorInvocation;
-import org.eclipse.jdt.core.dom.EnumConstantDeclaration;
 import org.eclipse.jdt.core.dom.Expression;
 import org.eclipse.jdt.core.dom.ExpressionStatement;
 import org.eclipse.jdt.core.dom.IBinding;
@@ -49,8 +44,6 @@
 import org.eclipse.jdt.core.dom.SimpleName;
 import org.eclipse.jdt.core.dom.SingleVariableDeclaration;
 import org.eclipse.jdt.core.dom.Statement;
-import org.eclipse.jdt.core.dom.StructuralPropertyDescriptor;
-import org.eclipse.jdt.core.dom.SuperConstructorInvocation;
 import org.eclipse.jdt.core.dom.SuperFieldAccess;
 import org.eclipse.jdt.core.dom.SuperMethodInvocation;
 import org.eclipse.jdt.core.dom.ThisExpression;
@@ -65,6 +58,7 @@
 import org.eclipse.jdt.internal.corext.codemanipulation.ContextSensitiveImportRewriteContext;
 import org.eclipse.jdt.internal.corext.codemanipulation.StubUtility2;
 import org.eclipse.jdt.internal.corext.dom.ASTNodeFactory;
+import org.eclipse.jdt.internal.corext.dom.ASTNodes;
 import org.eclipse.jdt.internal.corext.dom.Bindings;
 import org.eclipse.jdt.internal.corext.dom.HierarchicalASTVisitor;
 import org.eclipse.jdt.internal.corext.refactoring.structure.CompilationUnitRewrite;
@@ -75,7 +69,6 @@
 import org.eclipse.jdt.ui.cleanup.ICleanUpFix;
 
 import org.eclipse.jdt.internal.ui.preferences.JavaPreferencesSettings;
-import org.eclipse.jdt.internal.ui.text.correction.ASTResolving;
 
 public class LambdaExpressionsFix extends CompilationUnitRewriteOperationsFix {
 
@@ -251,8 +244,17 @@
 //				lambdaBody.accept(new InterfaceAccessQualifier(rewrite, classInstanceCreation.getType().resolveBinding())); //TODO: maybe need a separate ASTRewrite and string placeholder
 				
 				lambdaExpression.setBody(rewrite.createCopyTarget(lambdaBody));
-				rewrite.replace(classInstanceCreation, lambdaExpression, group);
-				
+				Expression replacement= lambdaExpression;
+				if (ASTNodes.isTargetAmbiguous(classInstanceCreation)) {
+					CastExpression cast= ast.newCastExpression();
+					cast.setExpression(lambdaExpression);
+					ImportRewrite importRewrite= cuRewrite.getImportRewrite();
+					ImportRewriteContext importRewriteContext= new ContextSensitiveImportRewriteContext(classInstanceCreation, importRewrite);
+					cast.setType(importRewrite.addImport(classInstanceCreation.getType().resolveBinding(), ast, importRewriteContext));
+					replacement= cast;
+				}
+				rewrite.replace(classInstanceCreation, replacement, group);
+
 				importRemover.registerRemovedNode(classInstanceCreation);
 				importRemover.registerRetainedNode(lambdaBody);
 			}
@@ -414,6 +416,10 @@
 	}
 
 	private static boolean isInTargetTypeContext(ClassInstanceCreation node) {
+		ITypeBinding targetType= ASTNodes.getTargetType(node);
+		return targetType != null && targetType.isFunctionalInterface();
+
+		/*
 		//TODO: probably incomplete, should reuse https://bugs.eclipse.org/bugs/show_bug.cgi?id=408966#c6
 		StructuralPropertyDescriptor locationInParent= node.getLocationInParent();
 		
@@ -445,5 +451,6 @@
 				|| locationInParent == ConditionalExpression.THEN_EXPRESSION_PROPERTY
 				|| locationInParent == ConditionalExpression.ELSE_EXPRESSION_PROPERTY
 				|| locationInParent == CastExpression.EXPRESSION_PROPERTY;
-		}
+		*/
+	}
 }