diff --git a/TODO.txt b/TODO.txt
new file mode 100644
index 000000000..eeae7d61b
--- /dev/null
+++ b/TODO.txt
@@ -0,0 +1,6 @@
+
+TODOS for release 4.1:
+======================
+
+ - mention in the release notes that COLLECTIONS-518 might break binary and source compatibility
+ but it would be unreasonable to instantiate an instance of class AbstractIterableGetMapDecorator
diff --git a/src/changes/changes.xml b/src/changes/changes.xml
index e91e364c8..8dc5859e7 100644
--- a/src/changes/changes.xml
+++ b/src/changes/changes.xml
@@ -22,6 +22,10 @@
+
+ The abstract decorator "AbstractIterableGetMapDecorator" was not declared
+ abstract.
+
Improved check for null input in "MapUtils#putAll(Map, Object[])".
diff --git a/src/main/java/org/apache/commons/collections4/splitmap/AbstractIterableGetMapDecorator.java b/src/main/java/org/apache/commons/collections4/splitmap/AbstractIterableGetMapDecorator.java
index 15a5f8866..519d424d4 100644
--- a/src/main/java/org/apache/commons/collections4/splitmap/AbstractIterableGetMapDecorator.java
+++ b/src/main/java/org/apache/commons/collections4/splitmap/AbstractIterableGetMapDecorator.java
@@ -31,7 +31,7 @@ import org.apache.commons.collections4.map.EntrySetToMapIteratorAdapter;
* @since 4.0
* @version $Id$
*/
-public class AbstractIterableGetMapDecorator implements IterableGet {
+public abstract class AbstractIterableGetMapDecorator implements IterableGet {
/** The map to decorate */
transient Map map;