diff --git a/src/math/Quaternion.js b/src/math/Quaternion.js
index 019823e932034a1641ac945348d8a064fa895846..5a8211993978351252244e2dcd2af1af41893771 100644
--- a/src/math/Quaternion.js
+++ b/src/math/Quaternion.js
@@ -18,7 +18,8 @@ function Quaternion( x, y, z, w ) {
 }
 
 Object.assign( Quaternion, {
-
+	isQuaternion: true,
+	
 	slerp: function ( qa, qb, qm, t ) {
 
 		return qm.copy( qa ).slerp( qb, t );