diff --git a/Semantic_Analizer_Tests/src/Basic_tests/OopNegativeSemanticTest.ttcn b/Semantic_Analizer_Tests/src/Basic_tests/OopNegativeSemanticTest.ttcn
index 86f09659c7a0439f8f993773c7ac85292b9541f1..10a66d267e02187cc634b6e6bcab4ad960259b47 100755
--- a/Semantic_Analizer_Tests/src/Basic_tests/OopNegativeSemanticTest.ttcn
+++ b/Semantic_Analizer_Tests/src/Basic_tests/OopNegativeSemanticTest.ttcn
@@ -211,6 +211,10 @@ type class ClassWithPrivate {
 	public function f_override3(in float pl_float) return integer {
 		return 1;
 	}
+	
+	public function f_override4() {
+		
+	}
 }
  
 type class ClassWithPrivateExt extends ClassWithPrivate {
@@ -225,6 +229,8 @@ type class ClassWithPrivateExt extends ClassWithPrivate {
 	public function f_override3(charstring pl_chr) return charstring {
 		return pl_chr;
 	}
+	
+	function f_override4() { }
 }
 
 // function with class parameter 
diff --git a/org.eclipse.titan.designer/src/org/eclipse/titan/designer/AST/TTCN3/types/ClassTypeBody.java b/org.eclipse.titan.designer/src/org/eclipse/titan/designer/AST/TTCN3/types/ClassTypeBody.java
index fb45fcf231ad897154cba97c800d73f2141e74db..20f7d88293052624c2f867a1dd521c0b56cd5d42 100755
--- a/org.eclipse.titan.designer/src/org/eclipse/titan/designer/AST/TTCN3/types/ClassTypeBody.java
+++ b/org.eclipse.titan.designer/src/org/eclipse/titan/designer/AST/TTCN3/types/ClassTypeBody.java
@@ -55,6 +55,7 @@ public final class ClassTypeBody extends TTCN3Scope implements IReferenceChainEl
 	public static final String HIDINGMODULEIDENTIFIER = "Inherited definition with name `{0}'' hides a module identifier";
 	public static final String FORMALPARAMSDIFFER = "Formal parameter list differs from previous definition";
 	public static final String OVERRIDDENFORMALPARAM = "Definition is overridden with different formal parameters";
+	public static final String PUBLICOVERRIDEPUBLIC = "Public method can only be overriden by a public method";
 	
 	public static final String TRAITMETHODSONLY = "Trait classes can only declare methods";
 	public static final String TRAITMETHODHASBODY = "Trait method cannot have a function body";
@@ -251,6 +252,9 @@ public final class ClassTypeBody extends TTCN3Scope implements IReferenceChainEl
 									localDefinition.getIdentifier().getLocation().reportSemanticError(FORMALPARAMSDIFFER);
 									definition.getIdentifier().getLocation().reportSemanticError(OVERRIDDENFORMALPARAM);
 								}
+								if (modifier == VisibilityModifier.Public && localDefinition.getVisibilityModifier() != VisibilityModifier.Public) {
+									localDefinition.getIdentifier().getLocation().reportSemanticError(PUBLICOVERRIDEPUBLIC);
+								}
 							}
 						} else {
 							localDefinition.getIdentifier().getLocation().reportSemanticError(MessageFormat.format(
diff --git a/org.eclipse.titan.regressiontests/src/org/eclipse/titan/regressiontests/designer/statictests/Basic_tests/OOP_Semantic_tests.java b/org.eclipse.titan.regressiontests/src/org/eclipse/titan/regressiontests/designer/statictests/Basic_tests/OOP_Semantic_tests.java
index 8148839463a1ed4f1fc4a42fac4e5612dab055d5..e08b27e414703623b3c0411860cc8df5a82d2a6b 100755
--- a/org.eclipse.titan.regressiontests/src/org/eclipse/titan/regressiontests/designer/statictests/Basic_tests/OOP_Semantic_tests.java
+++ b/org.eclipse.titan.regressiontests/src/org/eclipse/titan/regressiontests/designer/statictests/Basic_tests/OOP_Semantic_tests.java
@@ -45,7 +45,7 @@ public class OOP_Semantic_tests {
 
 	private ArrayList<MarkerToCheck> oopNegative_ttcn_initializer() {
 		//oopNegativeSemanticTest.ttcn
-		ArrayList<MarkerToCheck> markersToCheck = new ArrayList<MarkerToCheck>(44);
+		ArrayList<MarkerToCheck> markersToCheck = new ArrayList<MarkerToCheck>(45);
 		int lineNum = 28;
 		markersToCheck.add(new MarkerToCheck("class type expected",  lineNum, IMarker.SEVERITY_ERROR));
 		lineNum += 10;
@@ -100,11 +100,13 @@ public class OOP_Semantic_tests {
 		markersToCheck.add(new MarkerToCheck("Definition is overridden with different formal parameters",  lineNum, IMarker.SEVERITY_ERROR));
 		lineNum += 4;
 		markersToCheck.add(new MarkerToCheck("Definition is overridden with different formal parameters",  lineNum, IMarker.SEVERITY_ERROR));
-		lineNum += 10;
+		lineNum += 14;
 		markersToCheck.add(new MarkerToCheck("Formal parameter list differs from previous definition",  lineNum, IMarker.SEVERITY_ERROR));
 		lineNum += 4;
 		markersToCheck.add(new MarkerToCheck("Formal parameter list differs from previous definition",  lineNum, IMarker.SEVERITY_ERROR));
-		lineNum += 7;
+		lineNum += 4;
+		markersToCheck.add(new MarkerToCheck("Public method can only be overriden by a public method",  lineNum, IMarker.SEVERITY_ERROR));
+		lineNum += 5;
 		markersToCheck.add(new MarkerToCheck("Type mismatch: a value of type `integer' was expected instead of `float'",  lineNum, IMarker.SEVERITY_ERROR));
 		lineNum += 6;
 		markersToCheck.add(new MarkerToCheck("Class functions cannot have a `runs on` clause",  lineNum, IMarker.SEVERITY_ERROR));