diff --git a/query/plugins/org.eclipse.viatra.query.patternlanguage.emf/src/org/eclipse/viatra/query/patternlanguage/emf/validation/PatternLanguageValidator.java b/query/plugins/org.eclipse.viatra.query.patternlanguage.emf/src/org/eclipse/viatra/query/patternlanguage/emf/validation/PatternLanguageValidator.java
index dff32c9f4d..714f2744c8 100644
--- a/query/plugins/org.eclipse.viatra.query.patternlanguage.emf/src/org/eclipse/viatra/query/patternlanguage/emf/validation/PatternLanguageValidator.java
+++ b/query/plugins/org.eclipse.viatra.query.patternlanguage.emf/src/org/eclipse/viatra/query/patternlanguage/emf/validation/PatternLanguageValidator.java
@@ -531,7 +531,7 @@ private void executeDefaultAnnotationValidation(Annotation annotation, IPatternA
             Class<? extends ValueReference> expectedParameterType = validator.getExpectedParameterType(parameter);
             final ValueReference parameterValue = parameter.getValue();
             
-            if (expectedParameterType == null && parameterValue == null) {
+            if (expectedParameterType == null || parameterValue == null) {
                 return;
             }
             if (parameterValue instanceof JavaConstantValue) {