diff --git a/UnityCompatibilityTests.Unity35/Assets/Demigiant/DOTween/DOTween.dll b/UnityCompatibilityTests.Unity35/Assets/Demigiant/DOTween/DOTween.dll
index 485cfeb..71b4fd2 100644
Binary files a/UnityCompatibilityTests.Unity35/Assets/Demigiant/DOTween/DOTween.dll and b/UnityCompatibilityTests.Unity35/Assets/Demigiant/DOTween/DOTween.dll differ
diff --git a/UnityCompatibilityTests.Unity35/Assets/Demigiant/DOTween/DOTween.dll.mdb b/UnityCompatibilityTests.Unity35/Assets/Demigiant/DOTween/DOTween.dll.mdb
index 99dfdcb..3838cdf 100644
Binary files a/UnityCompatibilityTests.Unity35/Assets/Demigiant/DOTween/DOTween.dll.mdb and b/UnityCompatibilityTests.Unity35/Assets/Demigiant/DOTween/DOTween.dll.mdb differ
diff --git a/UnityTests.Unity4/Assets/Demigiant/DOTween/DOTween.dll b/UnityTests.Unity4/Assets/Demigiant/DOTween/DOTween.dll
index 485cfeb..71b4fd2 100644
Binary files a/UnityTests.Unity4/Assets/Demigiant/DOTween/DOTween.dll and b/UnityTests.Unity4/Assets/Demigiant/DOTween/DOTween.dll differ
diff --git a/UnityTests.Unity4/Assets/Demigiant/DOTween/DOTween.dll.mdb b/UnityTests.Unity4/Assets/Demigiant/DOTween/DOTween.dll.mdb
index 99dfdcb..3838cdf 100644
Binary files a/UnityTests.Unity4/Assets/Demigiant/DOTween/DOTween.dll.mdb and b/UnityTests.Unity4/Assets/Demigiant/DOTween/DOTween.dll.mdb differ
diff --git a/UnityTests.Unity5/Assets/Demigiant/DOTween/DOTween.dll b/UnityTests.Unity5/Assets/Demigiant/DOTween/DOTween.dll
index 485cfeb..71b4fd2 100644
Binary files a/UnityTests.Unity5/Assets/Demigiant/DOTween/DOTween.dll and b/UnityTests.Unity5/Assets/Demigiant/DOTween/DOTween.dll differ
diff --git a/UnityTests.Unity5/Assets/Demigiant/DOTween/DOTween.dll.mdb b/UnityTests.Unity5/Assets/Demigiant/DOTween/DOTween.dll.mdb
index 99dfdcb..3838cdf 100644
Binary files a/UnityTests.Unity5/Assets/Demigiant/DOTween/DOTween.dll.mdb and b/UnityTests.Unity5/Assets/Demigiant/DOTween/DOTween.dll.mdb differ
diff --git a/_DOTween.Assembly/DOTween/TweenSettingsExtensions.cs b/_DOTween.Assembly/DOTween/TweenSettingsExtensions.cs
index 8ce3252..13617de 100644
--- a/_DOTween.Assembly/DOTween/TweenSettingsExtensions.cs
+++ b/_DOTween.Assembly/DOTween/TweenSettingsExtensions.cs
@@ -402,7 +402,7 @@ namespace DG.Tweening
         public static Sequence Append(this Sequence s, Tween t)
         {
             if (s == null || !s.active || s.creationLocked) return s;
-            if (t == null || !t.active) return s;
+            if (t == null || !t.active || t.isSequenced) return s;
 
             Sequence.DoInsert(s, t, s.duration);
             return s;
@@ -413,7 +413,7 @@ namespace DG.Tweening
         public static Sequence Prepend(this Sequence s, Tween t)
         {
             if (s == null || !s.active || s.creationLocked) return s;
-            if (t == null || !t.active) return s;
+            if (t == null || !t.active || t.isSequenced) return s;
 
             Sequence.DoPrepend(s, t);
             return s;
@@ -423,7 +423,7 @@ namespace DG.Tweening
         public static Sequence Join(this Sequence s, Tween t)
         {
             if (s == null || !s.active || s.creationLocked) return s;
-            if (t == null || !t.active) return s;
+            if (t == null || !t.active || t.isSequenced) return s;
 
             Sequence.DoInsert(s, t, s.lastTweenInsertTime);
             return s;
@@ -436,7 +436,7 @@ namespace DG.Tweening
         public static Sequence Insert(this Sequence s, float atPosition, Tween t)
         {
             if (s == null || !s.active || s.creationLocked) return s;
-            if (t == null || !t.active) return s;
+            if (t == null || !t.active || t.isSequenced) return s;
 
             Sequence.DoInsert(s, t, atPosition);
             return s;
diff --git a/_DOTween.Assembly/bin/DOTween.dll b/_DOTween.Assembly/bin/DOTween.dll
index 485cfeb..71b4fd2 100644
Binary files a/_DOTween.Assembly/bin/DOTween.dll and b/_DOTween.Assembly/bin/DOTween.dll differ
diff --git a/_DOTween.Assembly/bin/DOTween.dll.mdb b/_DOTween.Assembly/bin/DOTween.dll.mdb
index 99dfdcb..3838cdf 100644
Binary files a/_DOTween.Assembly/bin/DOTween.dll.mdb and b/_DOTween.Assembly/bin/DOTween.dll.mdb differ