diff --git a/jcommons/org.eclipse.statet.jcommons.util/src/org/eclipse/statet/jcommons/collections/CopyOnWriteIdentityListSet.java b/jcommons/org.eclipse.statet.jcommons.util/src/org/eclipse/statet/jcommons/collections/CopyOnWriteIdentityListSet.java
index 4791b3b..37b05d2 100644
--- a/jcommons/org.eclipse.statet.jcommons.util/src/org/eclipse/statet/jcommons/collections/CopyOnWriteIdentityListSet.java
+++ b/jcommons/org.eclipse.statet.jcommons.util/src/org/eclipse/statet/jcommons/collections/CopyOnWriteIdentityListSet.java
@@ -51,7 +51,7 @@
 		this.list= ImCollections.newIdentityList();
 	}
 	
-	public CopyOnWriteIdentityListSet(final Set<E> initialSet) {
+	public CopyOnWriteIdentityListSet(final Set<? extends E> initialSet) {
 		this.list= ImCollections.toIdentityList(initialSet);
 	}
 	
diff --git a/jcommons/org.eclipse.statet.jcommons.util/src/org/eclipse/statet/jcommons/collections/CopyOnWriteList.java b/jcommons/org.eclipse.statet.jcommons.util/src/org/eclipse/statet/jcommons/collections/CopyOnWriteList.java
index 049abfc..7161db1 100644
--- a/jcommons/org.eclipse.statet.jcommons.util/src/org/eclipse/statet/jcommons/collections/CopyOnWriteList.java
+++ b/jcommons/org.eclipse.statet.jcommons.util/src/org/eclipse/statet/jcommons/collections/CopyOnWriteList.java
@@ -61,7 +61,7 @@
 		this.list= ImCollections.newList();
 	}
 	
-	public CopyOnWriteList(final List<E> initialList) {
+	public CopyOnWriteList(final List<? extends E> initialList) {
 		this.list= ImCollections.toList(initialList);
 	}
 	
diff --git a/jcommons/org.eclipse.statet.jcommons.util/src/org/eclipse/statet/jcommons/collections/CopyOnWriteListSet.java b/jcommons/org.eclipse.statet.jcommons.util/src/org/eclipse/statet/jcommons/collections/CopyOnWriteListSet.java
index e8d1742..d9ea6ec 100644
--- a/jcommons/org.eclipse.statet.jcommons.util/src/org/eclipse/statet/jcommons/collections/CopyOnWriteListSet.java
+++ b/jcommons/org.eclipse.statet.jcommons.util/src/org/eclipse/statet/jcommons/collections/CopyOnWriteListSet.java
@@ -61,7 +61,7 @@
 		this.list= ImCollections.newList();
 	}
 	
-	public CopyOnWriteListSet(final Set<E> initialSet) {
+	public CopyOnWriteListSet(final Set<? extends E> initialSet) {
 		this.list= ImCollections.toList(initialSet);
 	}