diff --git a/sources/zweic/Analyzer.scala b/sources/zweic/Analyzer.scala
index 2ae6212..ae4846d 100755
--- a/sources/zweic/Analyzer.scala
+++ b/sources/zweic/Analyzer.scala
@@ -268,10 +268,8 @@
 		val t1 = analyzeExpr(varScope, left);
 		val t2 = analyzeExpr(varScope, right);
 		if ( op == EQ || op == NE ) {
-			t1.lub(t2) match {
-				case None =>
+			if (!( t1.isSubtype(t2) || t2.isSubtype(t1) )) {
 					Report.error(tree.pos, "incompatible types: " + t1 + " <=> " + t2);
-				case _ => ()
 			}
 		} else {
 			checkIntType(left.pos, t1);