diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9edd0e1..e67dd73 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,12 @@
 # 変更履歴
 
+## 4.0.1 (2024-10-12)
+
+* macro.mac: マクロの引数に式を指定すると正しく展開されない不具合を修正。
+  * `STRCPY`、`STRCAT`マクロの`rewind`引数
+  * `STREND`、`STRLEN`マクロの`offset`引数
+
+
 ## 4.0.0 (2024-10-06)
 
 * dosdef.mac, filesys.mac: 削除予定の機能はシンボル`__RUKA_ENABLE_OBSOLETE_MACRO__`を
diff --git a/src/macro.mac b/src/macro.mac
index bb84a78..8229da5 100644
--- a/src/macro.mac
+++ b/src/macro.mac
@@ -1,7 +1,7 @@
 .nlist
 
 ;macro.mac - RUKA assembler macro for X680x0/Human68k(v3) by TcbnErik
-;Last-modified: 2024-10-06
+;Last-modified: 2024-10-12
 ;
 ;Copying and distribution of this file, with or without modification,
 ;are permitted in any medium without royalty provided the copyright
@@ -65,7 +65,7 @@ STRCPY: .macro src,dst,rewind
     move.b (src)+,(dst)+
   bne @loop
   .if argc>=3
-    subq.l #-rewind,dst
+    subq.l #-(rewind),dst
   .endif
 .endm
 
@@ -76,10 +76,10 @@ STREND: .macro areg,offset
   bne @loop
   .if argc<=1
     subq.l #1,areg
-  .elif offset<=0
-    subq.l #1-offset,areg
-  .elif offset>=2
-    addq.l #offset-1,areg
+  .elif (offset)<=0
+    subq.l #1-(offset),areg
+  .elif (offset)>=2
+    addq.l #(offset)-1,areg
   .endif
 .endm