diff --git a/ChangeLog b/ChangeLog
index 9a74c18..3bd975a 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2013-11-27  Niibe Yutaka  <gniibe@fsij.org>
+
+	* src/stm32f103.h (AFIO_MAPR_SWJ_CFG_DISABLE): New.
+	* src/sys.c: Likewise.
+
 2013-11-26  Niibe Yutaka  <gniibe@fsij.org>
 
 	* src/usb_desc.c (hid_report_desc): New.
diff --git a/chopstx b/chopstx
index 2327cd9..f344d92 160000
--- a/chopstx
+++ b/chopstx
@@ -1 +1 @@
-Subproject commit 2327cd9013d6594def9486d890146e2c208cf5fa
+Subproject commit f344d926c1afafb9368a19e45db40fc312928a3c
diff --git a/src/stm32f103.h b/src/stm32f103.h
index bd6fa5d..f7ec6a2 100644
--- a/src/stm32f103.h
+++ b/src/stm32f103.h
@@ -697,3 +697,4 @@ static struct AFIO *const AFIO = (struct AFIO *const)AFIO_BASE;
 #define AFIO_EXTICR2_EXTI7_PD 0x3000
 
 #define AFIO_MAPR_TIM3_REMAP_PARTIALREMAP 0x00000800
+#define AFIO_MAPR_SWJ_CFG_DISABLE         0x04000000
diff --git a/src/sys.c b/src/sys.c
index 75fe7d2..c1d7ddd 100644
--- a/src/sys.c
+++ b/src/sys.c
@@ -207,6 +207,7 @@ struct AFIO
 static struct AFIO *const AFIO = (struct AFIO *const)AFIO_BASE;
 
 #define AFIO_MAPR_TIM3_REMAP_PARTIALREMAP 0x00000800
+#define AFIO_MAPR_SWJ_CFG_DISABLE         0x04000000
 
 
 struct GPIO {