diff --git a/src/test/java/typeinference/UnifyTest.java b/src/test/java/typeinference/UnifyTest.java
index c080a8605..41616a4f1 100644
--- a/src/test/java/typeinference/UnifyTest.java
+++ b/src/test/java/typeinference/UnifyTest.java
@@ -63,25 +63,25 @@ public class UnifyTest {
         Set<UnifyPair> constraints = new HashSet<>();
         type1 = new ReferenceType("Object");
         type2 = new ReferenceType("String");
-        constraints.add(new UnifyPair(type1, type2, PairOperator.SMALLER));
+        constraints.add(new UnifyPair(type2, type1, PairOperator.SMALLER));
         type1 = new ReferenceType("Number");
         type2 = new ReferenceType("Integer");
-        constraints.add(new UnifyPair(type1, type2, PairOperator.SMALLER));
+        constraints.add(new UnifyPair(type2, type1, PairOperator.SMALLER));
         type1 = new ReferenceType("Object");
         type2 = new ReferenceType("Number");
-        constraints.add(new UnifyPair(type1, type2, PairOperator.SMALLER));
+        constraints.add(new UnifyPair(type2, type1, PairOperator.SMALLER));
        /* type1 = new ReferenceType("AbstractList", new TypeParams(new PlaceholderType("X")));
         type2 = new ReferenceType("List", new TypeParams(new PlaceholderType("X")));
         constraints.add(new UnifyPair(type1, type2, PairOperator.SMALLER));
         type1 = new ReferenceType("Object");
         type2 = new ReferenceType("AbstractList", new TypeParams(new PlaceholderType("X")));
         constraints.add(new UnifyPair(type1, type2, PairOperator.SMALLER));*/
-        type1 = new ReferenceType("AbstractList");
-        type2 = new ReferenceType("List");
-        constraints.add(new UnifyPair(type1, type2, PairOperator.SMALLER));
+        type1 = new ReferenceType("AbstractList", new PlaceholderType("X"));
+        type2 = new ReferenceType("List", new PlaceholderType("X"));
+        constraints.add(new UnifyPair(type2, type1, PairOperator.SMALLER));
         type1 = new ReferenceType("Object");
-        type2 = new ReferenceType("AbstractList");
-        constraints.add(new UnifyPair(type1, type2, PairOperator.SMALLER));
+        type2 = new ReferenceType("AbstractList", new PlaceholderType("X"));
+        constraints.add(new UnifyPair(type2, type1, PairOperator.SMALLER));
 
         IFiniteClosure finiteClosure = new FiniteClosure(constraints, new NullWriter());
 
@@ -106,11 +106,11 @@ public class UnifyTest {
 
         Set<UnifyPair> constraints = new HashSet<>();
         type1 = new ReferenceType("Object");
-        type2 = new ReferenceType("List");
-        constraints.add(new UnifyPair(type1, type2, PairOperator.SMALLER));
+        type2 = new ReferenceType("List", new PlaceholderType("X"));
+        constraints.add(new UnifyPair(type2, type1, PairOperator.SMALLER));
         type1 = new ReferenceType("Object");
         type2 = new ReferenceType("Integer");
-        constraints.add(new UnifyPair(type1, type2, PairOperator.SMALLER));
+        constraints.add(new UnifyPair(type2, type1, PairOperator.SMALLER));
 
         IFiniteClosure finiteClosure = new FiniteClosure(constraints, new NullWriter());