diff --git a/pkg/exprparser/interpreter.go b/pkg/exprparser/interpreter.go
index ea91271..ef3e8e1 100644
--- a/pkg/exprparser/interpreter.go
+++ b/pkg/exprparser/interpreter.go
@@ -372,8 +372,16 @@ func (impl *interperterImpl) compareValues(leftValue reflect.Value, rightValue r
 
 		return impl.compareNumber(leftValue.Float(), rightValue.Float(), kind)
 
+	case reflect.Invalid:
+		if rightValue.Kind() == reflect.Invalid {
+			return true, nil
+		}
+
+		// not possible situation - params are converted to the same type in code above
+		return nil, fmt.Errorf("Compare params of Invalid type: left: %+v, right: %+v", leftValue.Kind(), rightValue.Kind())
+
 	default:
-		return nil, fmt.Errorf("TODO: evaluateCompare not implemented! left: %+v, right: %+v", leftValue.Kind(), rightValue.Kind())
+		return nil, fmt.Errorf("Compare not implemented for types: left: %+v, right: %+v", leftValue.Kind(), rightValue.Kind())
 	}
 }
 
diff --git a/pkg/exprparser/interpreter_test.go b/pkg/exprparser/interpreter_test.go
index d6f58a7..01eb25f 100644
--- a/pkg/exprparser/interpreter_test.go
+++ b/pkg/exprparser/interpreter_test.go
@@ -69,6 +69,11 @@ func TestOperators(t *testing.T) {
 		{`true || false`, true, "or", ""},
 		{`fromJSON('{}') && true`, true, "and-boolean-object", ""},
 		{`fromJSON('{}') || false`, make(map[string]interface{}), "or-boolean-object", ""},
+		{"github.event.commits[0].author.username != github.event.commits[1].author.username", true, "property-comparison1", ""},
+		{"github.event.commits[0].author.username1 != github.event.commits[1].author.username", true, "property-comparison2", ""},
+		{"github.event.commits[0].author.username != github.event.commits[1].author.username1", true, "property-comparison3", ""},
+		{"github.event.commits[0].author.username1 != github.event.commits[1].author.username2", true, "property-comparison4", ""},
+		{"secrets != env", nil, "property-comparison5", "Compare not implemented for types: left: map, right: map"},
 	}
 
 	env := &EvaluationEnvironment{