diff --git a/src/massive/munit/Assert.hx b/src/massive/munit/Assert.hx
index 87b07fd..6fc0cff 100644
--- a/src/massive/munit/Assert.hx
+++ b/src/massive/munit/Assert.hx
@@ -151,7 +151,7 @@ class Assert
 	public static function isType(value:Dynamic, type:Dynamic, ?message:String, ?info:PosInfos)
 	{
 		assertionCount++;
-		if(Std.is(value, type)) return;
+		if(isOfType(value, type)) return;
 		if(message == null) message = "Value [" + value + "] was not of type: " + Type.getClassName(type);
 		fail(message, info);
 	}
@@ -166,7 +166,7 @@ class Assert
 	public static function isNotType(value:Dynamic, type:Dynamic, ?message:String, ?info:PosInfos)
 	{
 		assertionCount++;
-		if(!Std.is(value, type)) return;
+		if(!isOfType(value, type)) return;
 		if(message == null) message = "Value [" + value + "] was of type: " + Type.getClassName(type);
 		fail(message, info);
 	}
@@ -290,7 +290,7 @@ class Assert
 		}
 		catch (e:Dynamic)
 		{
-			if(Std.is(e, expectedType)) return e;
+			if(isOfType(e, expectedType)) return e;
 			Assert.fail('Expected exception of type ${Type.getClassName(expectedType)} but got ${Type.getClassName(Type.getClass(e))}: ${e}');
 		}
 		return null;
@@ -334,8 +334,8 @@ class Assert
 			case TFunction: Reflect.compareMethods(a, b);
 			case TClass(_):
 				if(a == b) return true;
-				if(Std.is(a, String) && Std.is(b, String)) return false; // previous comparison failed
-				if(Std.is(a, Array) && Std.is(b, Array)) {
+				if(isOfType(a, String) && isOfType(b, String)) return false; // previous comparison failed
+				if(isOfType(a, Array) && isOfType(b, Array)) {
 					var a:Array<Dynamic> = cast a;
 					var b:Array<Dynamic> = cast b;
 					if(a.length != b.length) return false;
@@ -344,7 +344,7 @@ class Assert
 					}
 					return true;
 				}
-				if(Std.is(a, Bytes) && Std.is(b, Bytes)) {
+				if(isOfType(a, Bytes) && isOfType(b, Bytes)) {
 					var a = cast(a, Bytes);
 					var b = cast(b, Bytes);
 					if(a.length != b.length) return false;
@@ -353,7 +353,7 @@ class Assert
 					}
 					return true;
 				}
-				if(Std.is(a, IMap) && Std.is(b, IMap)) {
+				if(isOfType(a, IMap) && isOfType(b, IMap)) {
 					var a:IMap<Dynamic, Dynamic> = cast a;
 					var b:IMap<Dynamic, Dynamic> = cast b;
 					var akeys = [for(it in a.keys()) it];
@@ -364,7 +364,7 @@ class Assert
 					}
 					return true;
 				}
-				if(Std.is(a, Date) && Std.is(b, Date)) {
+				if(isOfType(a, Date) && isOfType(b, Date)) {
 					var a = cast(a, Date).getTime();
 					var b = cast(b, Date).getTime();
 					return a == b;
@@ -381,7 +381,7 @@ class Assert
 				}
 				return true;
 			case TObject:
-				if(Std.is(a, Class) && Std.is(b, Class)) {
+				if(isOfType(a, Class) && isOfType(b, Class)) {
 					var a = Type.getClassName(a);
 					var b = Type.getClassName(b);
 					return a == b;
@@ -417,9 +417,9 @@ class Assert
 	}
 	
 	static inline function empty(anObject:StringOrIterable):Bool {
-		if(Std.is(anObject, String)) {
+		if(isOfType(anObject, String)) {
 			return (anObject:String).length == 0;
-		} else if(Std.is(anObject, Array)) {
+		} else if(isOfType(anObject, Array)) {
 			var a:Array<Dynamic> = cast anObject;
 			return a.length == 0;
 		} else {
diff --git a/src/massive/munit/TestResult.hx b/src/massive/munit/TestResult.hx
index a6f764e..7778b39 100644
--- a/src/massive/munit/TestResult.hx
+++ b/src/massive/munit/TestResult.hx
@@ -110,8 +110,7 @@ class TestResult
 
 }
 
-@:enum
-abstract TestResultType(String) to String
+enum abstract TestResultType(String) to String
 {
 	var UNKNOWN = "UNKNOWN";
 	var PASS = "PASS";
diff --git a/src/massive/munit/TestRunner.hx b/src/massive/munit/TestRunner.hx
index 03bdbc0..d66b307 100644
--- a/src/massive/munit/TestRunner.hx
+++ b/src/massive/munit/TestRunner.hx
@@ -189,7 +189,13 @@ class TestRunner implements IAsyncDelegateObserver
 
         #if (neko || cpp || java || hl || eval)
 		var self = this;
-		var runThread:Thread = Thread.create(function()
+		var createThread = Thread.create;
+        #if haxe4 
+        #if (haxe >= version("4.2.0-rc.1"))
+        createThread = Thread.createWithEventLoop;
+        #end
+        #end
+        var runThread:Thread = createThread(function()
 		{
 			self.execute();
 			while (self.running)
@@ -235,7 +241,7 @@ class TestRunner implements IAsyncDelegateObserver
             var time:Float = Timer.stamp() - startTime;
             for (client in clients)
             {
-                if(Std.is(client, IAdvancedTestResultClient))
+                if(isOfType(client, IAdvancedTestResultClient))
                 {
                     var cl:IAdvancedTestResultClient = cast client;
                     cl.setCurrentTestClass(null);
@@ -249,7 +255,7 @@ class TestRunner implements IAsyncDelegateObserver
     {
         for(c in clients)
         {
-            if(Std.is(c, IAdvancedTestResultClient) && activeHelper.hasNext())
+            if(isOfType(c, IAdvancedTestResultClient) && activeHelper.hasNext())
 			{
 				var cl:IAdvancedTestResultClient = cast c;
 				cl.setCurrentTestClass(activeHelper.className);
@@ -310,11 +316,11 @@ class TestRunner implements IAsyncDelegateObserver
             }
 
 			#if hamcrest
-			if (Std.is(e, org.hamcrest.AssertionException))
+			if (isOfType(e, org.hamcrest.AssertionException))
 				e = new AssertionException(e.message, e.info);
 			#end
 
-            if (Std.is(e, AssertionException))
+            if (isOfType(e, AssertionException))
             {
                 result.executionTime = Timer.stamp() - testStartTime;
                 result.failure = e;
@@ -325,7 +331,7 @@ class TestRunner implements IAsyncDelegateObserver
             else
             {
                 result.executionTime = Timer.stamp() - testStartTime;
-                if (!Std.is(e, MUnitException))
+                if (!isOfType(e, MUnitException))
                     e = new UnhandledException(e, result.location);
 
                 result.error = e;
diff --git a/src/massive/munit/UnhandledException.hx b/src/massive/munit/UnhandledException.hx
index df91fba..62c1108 100644
--- a/src/massive/munit/UnhandledException.hx
+++ b/src/massive/munit/UnhandledException.hx
@@ -62,7 +62,7 @@ class UnhandledException extends MUnitException
 	{
 		var s = "";
 		#if flash
-		if (Std.is(source, flash.errors.Error) && flash.system.Capabilities.isDebugger)
+		if (isOfType(source, flash.errors.Error) && flash.system.Capabilities.isDebugger)
 		{
 			var lines = source.getStackTrace().split("\n");
 			lines.shift(); // remove repeated error name
@@ -71,7 +71,7 @@ class UnhandledException extends MUnitException
 		#end
 		if (s == "")
 		{
-			var stack:Array<haxe.StackItem> = CallStack.exceptionStack();
+			var stack:Array<haxe.CallStack.StackItem> = CallStack.exceptionStack();
 			while (stack.length > 0)
 			{
 				switch (stack.shift()) 
diff --git a/src/massive/munit/client/HTTPClient.hx b/src/massive/munit/client/HTTPClient.hx
index b72d873..ecad2ae 100644
--- a/src/massive/munit/client/HTTPClient.hx
+++ b/src/massive/munit/client/HTTPClient.hx
@@ -107,7 +107,7 @@ class HTTPClient implements IAdvancedTestResultClient
 	 */
 	public function setCurrentTestClass(className:String)
 	{
-		if(Std.is(client, IAdvancedTestResultClient))
+		if(isOfType(client, IAdvancedTestResultClient))
 		{
 			cast(client, IAdvancedTestResultClient).setCurrentTestClass(className);
 		}
diff --git a/src/massive/munit/client/PrintClientBase.hx b/src/massive/munit/client/PrintClientBase.hx
index 5cda00c..18a6afb 100644
--- a/src/massive/munit/client/PrintClientBase.hx
+++ b/src/massive/munit/client/PrintClientBase.hx
@@ -406,7 +406,7 @@ class ExternalPrintClientJS implements ExternalPrintClient
 		#end
 		
 		var a:Array<Dynamic> = [];
-		if(Std.is(args, Array)) a = a.concat(cast(args, Array<Dynamic>));
+		if(isOfType(args, Array)) a = a.concat(cast(args, Array<Dynamic>));
 		else a.push(args);
 		var jsCode = convertToJavaScript(method, a);
 		#if js
diff --git a/src/massive/munit/import.hx b/src/massive/munit/import.hx
new file mode 100644
index 0000000..edf59db
--- /dev/null
+++ b/src/massive/munit/import.hx
@@ -0,0 +1,11 @@
+package massive.munit;
+
+#if haxe4
+    #if (haxe >= version("4.1.0"))
+    import Std.isOfType as isOfType;
+    #else
+    import Std.is as isOfType;
+    #end
+#else
+import Std.is as isOfType;
+#end
\ No newline at end of file