diff --git a/src/main/java/org/warp/commonutils/type/Bytes.java b/src/main/java/org/warp/commonutils/type/Bytes.java
index 2ed35cf..15b6505 100644
--- a/src/main/java/org/warp/commonutils/type/Bytes.java
+++ b/src/main/java/org/warp/commonutils/type/Bytes.java
@@ -1,7 +1,6 @@
 package org.warp.commonutils.type;
 
 import it.unimi.dsi.fastutil.objects.ObjectOpenHashSet;
-import it.unimi.dsi.fastutil.objects.ObjectSets.UnmodifiableSet;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
diff --git a/src/main/java/org/warp/commonutils/type/UnmodifiableIterableSet.java b/src/main/java/org/warp/commonutils/type/UnmodifiableIterableSet.java
index f3b35fc..618281f 100644
--- a/src/main/java/org/warp/commonutils/type/UnmodifiableIterableSet.java
+++ b/src/main/java/org/warp/commonutils/type/UnmodifiableIterableSet.java
@@ -4,6 +4,7 @@ import it.unimi.dsi.fastutil.objects.ObjectOpenHashSet;
 import it.unimi.dsi.fastutil.objects.ObjectSets;
 import java.util.Arrays;
 import java.util.Collections;
+import java.util.HashSet;
 import java.util.Iterator;
 import java.util.NoSuchElementException;
 import java.util.Set;
@@ -70,7 +71,7 @@ public interface UnmodifiableIterableSet<K> extends Iterable<K> {
 				@Override
 				public Set<K> toUnmodifiableSet() {
 					//noinspection unchecked
-					return ObjectSets.EMPTY_SET;
+					return new HashSet<>(0);
 				}
 
 				@Override
@@ -120,7 +121,7 @@ public interface UnmodifiableIterableSet<K> extends Iterable<K> {
 
 			@Override
 			public Set<K> toUnmodifiableSet() {
-				return ObjectSets.unmodifiable(new ObjectOpenHashSet<>(items, 1.0f));
+				return new HashSet<>(Arrays.asList(items));
 			}
 
 			@Override
diff --git a/src/main/java/org/warp/commonutils/type/UnmodifiableSet.java b/src/main/java/org/warp/commonutils/type/UnmodifiableSet.java
index 6442d79..99622f2 100644
--- a/src/main/java/org/warp/commonutils/type/UnmodifiableSet.java
+++ b/src/main/java/org/warp/commonutils/type/UnmodifiableSet.java
@@ -6,6 +6,7 @@ import it.unimi.dsi.fastutil.objects.ObjectOpenHashSet;
 import it.unimi.dsi.fastutil.objects.ObjectSet;
 import it.unimi.dsi.fastutil.objects.ObjectSets;
 import java.util.Collections;
+import java.util.HashSet;
 import java.util.Iterator;
 import java.util.NoSuchElementException;
 import java.util.Set;
@@ -96,7 +97,7 @@ public interface UnmodifiableSet<K> extends UnmodifiableIterableSet<K> {
 		@Override
 		public Set<K> toUnmodifiableSet() {
 			//noinspection unchecked
-			return ObjectSets.EMPTY_SET;
+			return new HashSet<>();
 		}
 
 		@Override