diff --git a/confidence-incubator/src/main/java/org/saynotobugs/confidence/junit5/engine/assertion/AssertionThat.java b/confidence-incubator/src/main/java/org/saynotobugs/confidence/junit5/engine/assertion/AssertionThat.java
index 99d8cf0..a172083 100644
--- a/confidence-incubator/src/main/java/org/saynotobugs/confidence/junit5/engine/assertion/AssertionThat.java
+++ b/confidence-incubator/src/main/java/org/saynotobugs/confidence/junit5/engine/assertion/AssertionThat.java
@@ -30,10 +30,10 @@ public final class AssertionThat<T> implements Assertion
 {
     private final String mName;
     private final T mInstance;
-    private final Quality<T> mQuality;
+    private final Quality<? super T> mQuality;
 
 
-    public AssertionThat(String name, T instance, Quality<T> quality)
+    public AssertionThat(String name, T instance, Quality<? super T> quality)
     {
         mName = name;
         mInstance = instance;
@@ -41,7 +41,7 @@ public AssertionThat(String name, T instance, Quality<T> quality)
     }
 
 
-    public AssertionThat(T instance, Quality<T> quality)
+    public AssertionThat(T instance, Quality<? super T> quality)
     {
         this("", instance, quality);
     }