diff --git a/src/main/java/de/tlc4b/TLC4B.java b/src/main/java/de/tlc4b/TLC4B.java
index 3e341c9e95c5c1ad96a04510fa22657c3aa288a2..403a33a48e66c1783403780c150e6dbc2be1ce87 100644
--- a/src/main/java/de/tlc4b/TLC4B.java
+++ b/src/main/java/de/tlc4b/TLC4B.java
@@ -401,13 +401,6 @@ public class TLC4B {
 	}
 
 	private void handleMainFileName() {
-		// the following lines fix incorrect file names
-		filename = filename.replace("\\", File.separator);
-		filename = filename.replace("/", File.separator);
-		if (!filename.toLowerCase().endsWith(".mch") && !filename.toLowerCase().endsWith(".sys")) {
-			filename = filename + ".mch";
-		}
-
 		mainfile = new File(filename);
 		if (!mainfile.exists()) {
 			throw new TLC4BIOException("The file " + mainfile.getPath() + " does not exist.");
diff --git a/src/test/java/de/tlc4b/tlc/integration/LTLTest.java b/src/test/java/de/tlc4b/tlc/integration/LTLTest.java
index 8cbe47c53665240206a277df524e7d86ea96b913..63f87ae87de9945aec9ddcb9bb5a6e4240ffcc21 100644
--- a/src/test/java/de/tlc4b/tlc/integration/LTLTest.java
+++ b/src/test/java/de/tlc4b/tlc/integration/LTLTest.java
@@ -20,43 +20,43 @@ public class LTLTest {
 
 	@Test
 	public void testCounterLTL() throws Exception {
-		String[] a = new String[] { ".\\src\\test\\resources\\ltl\\CounterLTL.mch" };
+		String[] a = new String[] { "src/test/resources/ltl/CounterLTL.mch" };
 		assertEquals(NoError, test(a));
 	}
 	
 	@Test
 	public void testCounterError() throws Exception {
-		String[] a = new String[] { ".\\src\\test\\resources\\ltl\\CounterError.mch" };
+		String[] a = new String[] { "src/test/resources/ltl/CounterError.mch" };
 		assertEquals(TemporalPropertyViolation, test(a));
 	}
 
 	@Test
 	public void testFairnessCounterLTL() throws Exception {
-		String[] a = new String[] { ".\\src\\test\\resources\\ltl\\FairnessCounter.mch" };
+		String[] a = new String[] { "src/test/resources/ltl/FairnessCounter.mch" };
 		assertEquals(NoError, test(a));
 	}
 
 	@Test
 	public void testUniversalQuantificaitonLTL() throws Exception {
-		String[] a = new String[] { ".\\src\\test\\resources\\ltl\\UniveralQuatification.mch" };
+		String[] a = new String[] { "src/test/resources/ltl/UniveralQuatification.mch" };
 		assertEquals(TemporalPropertyViolation, test(a));
 	}
 
 	@Test
 	public void testExistentialQuantificationLTL() throws Exception {
-		String[] a = new String[] { ".\\src\\test\\resources\\ltl\\ExistentialQuantification.mch" };
+		String[] a = new String[] { "src/test/resources/ltl/ExistentialQuantification.mch" };
 		assertEquals(NoError, test(a));
 	}
 
 	@Test
 	public void testFairnessParameter() throws Exception {
-		String[] a = new String[] { ".\\src\\test\\resources\\ltl\\Fairness_Parameter.mch" };
+		String[] a = new String[] { "src/test/resources/ltl/Fairness_Parameter.mch" };
 		assertEquals(NoError, test(a));
 	}
 	
 	@Test
 	public void testLTLStatePropertyViolation() throws Exception{
-		String[] a = new String[] { ".\\src\\test\\resources\\ltl\\StatePropertyViolation.mch" };
+		String[] a = new String[] { "src/test/resources/ltl/StatePropertyViolation.mch" };
 		assertEquals(TemporalPropertyViolation, test(a));
 	}