diff --git a/li.strolch.utils/src/main/java/li/strolch/utils/collections/MapOfLists.java b/li.strolch.utils/src/main/java/li/strolch/utils/collections/MapOfLists.java
index 11f77bf5a..8527fc4e2 100644
--- a/li.strolch.utils/src/main/java/li/strolch/utils/collections/MapOfLists.java
+++ b/li.strolch.utils/src/main/java/li/strolch/utils/collections/MapOfLists.java
@@ -121,4 +121,11 @@ public class MapOfLists<T, U> {
 	public boolean isEmpty() {
 		return this.mapOfLists.isEmpty();
 	}
+
+	public MapOfLists<T, U> addAll(MapOfLists<T, U> other) {
+		for (T key : other.keySet()) {
+			addList(key, other.getList(key));
+		}
+		return this;
+	}
 }
diff --git a/li.strolch.utils/src/main/java/li/strolch/utils/collections/MapOfMaps.java b/li.strolch.utils/src/main/java/li/strolch/utils/collections/MapOfMaps.java
index c9fe1cc72..ca6338186 100644
--- a/li.strolch.utils/src/main/java/li/strolch/utils/collections/MapOfMaps.java
+++ b/li.strolch.utils/src/main/java/li/strolch/utils/collections/MapOfMaps.java
@@ -169,4 +169,11 @@ public class MapOfMaps<T, U, V> {
 	public boolean isEmpty() {
 		return this.mapOfMaps.isEmpty();
 	}
+
+	public MapOfMaps<T, U, V> putAll(MapOfMaps<T, U, V> other) {
+		for (T key : other.keySet()) {
+			addMap(key, other.getMap(key));
+		}
+		return this;
+	}
 }
diff --git a/li.strolch.utils/src/main/java/li/strolch/utils/collections/MapOfSets.java b/li.strolch.utils/src/main/java/li/strolch/utils/collections/MapOfSets.java
index 68efdf94e..fd820abff 100644
--- a/li.strolch.utils/src/main/java/li/strolch/utils/collections/MapOfSets.java
+++ b/li.strolch.utils/src/main/java/li/strolch/utils/collections/MapOfSets.java
@@ -120,4 +120,11 @@ public class MapOfSets<T, U> {
 	public boolean isEmpty() {
 		return this.mapOfSets.isEmpty();
 	}
+
+	public MapOfSets<T, U> addAll(MapOfSets<T, U> other) {
+		for (T key : other.keySet()) {
+			addSet(key, other.getSet(key));
+		}
+		return this;
+	}
 }