diff --git a/src/org/ntlab/deltaExtractor/DeltaExtractor.java b/src/org/ntlab/deltaExtractor/DeltaExtractor.java
index 36291dd..794b9a4 100644
--- a/src/org/ntlab/deltaExtractor/DeltaExtractor.java
+++ b/src/org/ntlab/deltaExtractor/DeltaExtractor.java
@@ -336,6 +336,15 @@
 								} else {
 									aliasCollector.addAlias(new DeltaAlias(Alias.AliasType.RECEIVER, 0, objList.get(retIndex), tracePoint.duplicate(), false));
 								}
+							} else if (objList.get(retIndex) == null) {
+								// static �Ăяo���������ꍇ
+								removeList.add(thisObjectId);		// ��ň�U�AthisObject ����菜��
+								isTrackingThis = true;				// �Ăяo�����T���O�ɕ���
+								if (isSrcSide) {
+									aliasCollector.addAlias(new DeltaAlias(Alias.AliasType.THIS, 0, thisObjectId, tracePoint.duplicate(), true));
+								} else {
+									aliasCollector.addAlias(new DeltaAlias(Alias.AliasType.THIS, 0, thisObjectId, tracePoint.duplicate(), false));
+								}
 							}
 							if (isLost) {
 								checkList.add(objList.get(retIndex));