diff --git a/src/refactor/refactor/ExtractInterface.hx b/src/refactor/refactor/ExtractInterface.hx
index ddd3034..249605f 100644
--- a/src/refactor/refactor/ExtractInterface.hx
+++ b/src/refactor/refactor/ExtractInterface.hx
@@ -291,7 +291,33 @@ class ExtractInterface {
 		for (field in fields) {
 			buf.add("\t");
 			var text:String = RefactorHelper.extractText(context.converter, extractData.content, field.pos.min, field.pos.max);
-			text = text.replace(" public ", " ");
+			var index = text.lastIndexOf("function ");
+			if (index < 0) {
+				index = text.lastIndexOf("var ");
+			}
+			if (index < 0) {
+				index = text.lastIndexOf("final ");
+			}
+			if (index > 0) {
+				var commentIndex:Int = text.lastIndexOf("*/", index);
+				var comment = "";
+				if (commentIndex < 0) {
+					commentIndex = 0;
+				}
+				if (commentIndex > 0) {
+					comment = text.substr(0, commentIndex);
+				}
+				var modifier = text.substring(commentIndex, index);
+				final funcSignature = text.substr(index);
+				modifier = modifier.replace("public", "");
+				modifier = modifier.replace("inline", "");
+				modifier = modifier.replace("override", "");
+				modifier = modifier.replace("abstract", "");
+				text = comment + modifier + funcSignature;
+				if (!funcSignature.endsWith(";")) {
+					text += ";";
+				}
+			}
 			buf.add(text);
 			if (field.isSharp) {
 				buf.add("\n");
diff --git a/src/refactor/rename/RenameHelper.hx b/src/refactor/rename/RenameHelper.hx
index 48cc2f1..4f93a2d 100644
--- a/src/refactor/rename/RenameHelper.hx
+++ b/src/refactor/rename/RenameHelper.hx
@@ -113,6 +113,18 @@ class RenameHelper {
 		}
 		name = name.substr(0, index);
 
+		function addMatchToChangelist(type:Type) {
+			if (!types.contains(type)) {
+				return;
+			}
+			var pos:IdentifierPos = {
+				fileName: use.pos.fileName,
+				start: use.pos.start + name.length + 1,
+				end: use.pos.end
+			};
+			pos.end = pos.start + fromName.length;
+			changelist.addChange(use.pos.fileName, ReplaceText(context.what.toName, pos, false), use);
+		}
 		var search:SearchTypeOf = {
 			name: name,
 			pos: use.pos.start,
@@ -122,20 +134,21 @@ class RenameHelper {
 			switch (typeHint) {
 				case null:
 				case ClasspathType(type, _):
-					for (t in types) {
-						if (t != type) {
-							continue;
-						}
-						var pos:IdentifierPos = {
-							fileName: use.pos.fileName,
-							start: use.pos.start + name.length + 1,
-							end: use.pos.end
-						};
-						pos.end = pos.start + fromName.length;
-						changelist.addChange(use.pos.fileName, ReplaceText(context.what.toName, pos, false), use);
+					addMatchToChangelist(type);
+				case LibType(name, fullName, params):
+					if (name != "Null") {
+						return;
 					}
-				case LibType(_, _) | UnknownType(_):
-				case FunctionType(_, _) | StructType(_):
+					if (params == null || params.length != 1) {
+						return;
+					}
+					switch (params[0]) {
+						case ClasspathType(type, _):
+							addMatchToChangelist(type);
+						case LibType(_) | FunctionType(_) | StructType(_) | UnknownType(_):
+					}
+
+				case UnknownType(_) | FunctionType(_, _) | StructType(_):
 			}
 		});
 	}
diff --git a/src/refactor/typing/TypingHelper.hx b/src/refactor/typing/TypingHelper.hx
index 5d5d28a..5c74bc8 100644
--- a/src/refactor/typing/TypingHelper.hx
+++ b/src/refactor/typing/TypingHelper.hx
@@ -164,7 +164,18 @@ class TypingHelper {
 					case ClasspathType(t, params):
 						return findField(context, t, part).then(findFieldForPart);
 					case LibType(t, fullPath, params):
-						return Promise.reject('unable to determine type of "$part" in ${searchTypeOf.defineType.name.name}@${searchTypeOf.pos}');
+						if (t != "Null") {
+							return Promise.reject('unable to determine type of "$part" in ${searchTypeOf.defineType.name.name}@${searchTypeOf.pos}');
+						}
+						if (params == null || params.length != 1) {
+							return Promise.reject('unable to determine type of "$part" in ${searchTypeOf.defineType.name.name}@${searchTypeOf.pos}');
+						}
+						switch (params[0]) {
+							case ClasspathType(t, typeParams):
+								return findField(context, t, part).then(findFieldForPart);
+							case LibType(_) | FunctionType(_) | StructType(_) | UnknownType(_):
+								return Promise.reject('unable to determine type of "$part" in ${searchTypeOf.defineType.name.name}@${searchTypeOf.pos}');
+						}
 					case StructType(fields):
 						return Promise.reject('unable to determine type of "$part" in ${searchTypeOf.defineType.name.name}@${searchTypeOf.pos}');
 					case FunctionType(args, retVal):
@@ -363,7 +374,9 @@ class TypingHelper {
 			if ((hint.uses == null) || (hint.uses.length <= 0)) {
 				return Promise.reject();
 			}
-			return typeFromTypeHint(context, hint.uses[0]);
+			return typeFromTypeHint(context, hint.uses[0]).then(function(typeHint) {
+				return Promise.resolve(LibType("Null", "Null", [typeHint]));
+			});
 		}
 
 		var parts:Array<String> = hint.name.split(".");
diff --git a/test/refactor/refactor/RefactorExtractMethodTest.hx b/test/refactor/refactor/RefactorExtractMethodTest.hx
index cb50996..d297513 100644
--- a/test/refactor/refactor/RefactorExtractMethodTest.hx
+++ b/test/refactor/refactor/RefactorExtractMethodTest.hx
@@ -209,6 +209,64 @@ class RefactorExtractMethodTest extends RefactorTestBase {
 		checkRefactor(RefactorExtractMethod, {fileName: "testcases/methods/Main.hx", posStart: 1365, posEnd: 1543}, edits, async);
 	}
 
+	function testDemoSimple(async:Async) {
+		var edits:Array<TestEdit> = [
+			makeReplaceTestEdit("testcases/methods/Demo.hx", "doSomethingExtract();\n", 161, 252, true),
+			makeInsertTestEdit("testcases/methods/Demo.hx",
+				"function doSomethingExtract() {\n"
+				+ "doNothing();\n"
+				+ "		trace(\"I'm here\");\n"
+				+ "		doNothing();\n"
+				+ "		trace(\"yep, still here\");\n"
+				+ "		doNothing();\n"
+				+ "}\n",
+				467, true),
+		];
+		checkRefactor(RefactorExtractMethod, {fileName: "testcases/methods/Demo.hx", posStart: 160, posEnd: 252}, edits, async);
+	}
+
+	function testDemoSwitch(async:Async) {
+		var edits:Array<TestEdit> = [
+			makeReplaceTestEdit("testcases/methods/Demo.hx", "doSomethingExtract(cond, val, text);\n", 262, 463, true),
+			makeInsertTestEdit("testcases/methods/Demo.hx",
+				"function doSomethingExtract(cond:Bool, val:Int, text:Null<String>) {\n"
+				+ "return switch [cond, val] {\n"
+				+ "			case [true, 0]:\n"
+				+ "				std.Math.random() * val;\n"
+				+ "			case [true, _]:\n"
+				+ "				val + val;\n"
+				+ "			case [false, 10]:\n"
+				+ "				Std.parseFloat(text);\n"
+				+ "			case [_, _]:\n"
+				+ "				std.Math.NEGATIVE_INFINITY;\n"
+				+ "		}\n"
+				+ "}\n",
+				467, true),
+		];
+		checkRefactor(RefactorExtractMethod, {fileName: "testcases/methods/Demo.hx", posStart: 262, posEnd: 463}, edits, async);
+	}
+
+	function testDemoReturnSwitch(async:Async) {
+		var edits:Array<TestEdit> = [
+			makeReplaceTestEdit("testcases/methods/Demo.hx", "return doSomethingExtract(cond, val, text);\n", 255, 463, true),
+			makeInsertTestEdit("testcases/methods/Demo.hx",
+				"function doSomethingExtract(cond:Bool, val:Int, text:Null<String>) {\n"
+				+ "return switch [cond, val] {\n"
+				+ "			case [true, 0]:\n"
+				+ "				std.Math.random() * val;\n"
+				+ "			case [true, _]:\n"
+				+ "				val + val;\n"
+				+ "			case [false, 10]:\n"
+				+ "				Std.parseFloat(text);\n"
+				+ "			case [_, _]:\n"
+				+ "				std.Math.NEGATIVE_INFINITY;\n"
+				+ "		}\n"
+				+ "}\n",
+				467, true),
+		];
+		checkRefactor(RefactorExtractMethod, {fileName: "testcases/methods/Demo.hx", posStart: 254, posEnd: 463}, edits, async);
+	}
+
 	function testCalculateMath(async:Async) {
 		var edits:Array<TestEdit> = [
 			makeReplaceTestEdit("testcases/methods/Math.hx", "calculateExtract(a, b);\n", 106, 122, true),