diff --git a/openocd/openocd.stm32f3-disco.cfg b/openocd/openocd.stm32f3-disco.cfg
index 066c12a..835d466 100644
--- a/openocd/openocd.stm32f3-disco.cfg
+++ b/openocd/openocd.stm32f3-disco.cfg
@@ -3,7 +3,7 @@ set WORKAREASIZE 0x4000
 source [find target/stm32f3x.cfg]
 
 # serial of my f3 disco board.
-hla_serial "S?n\x06gePQ6G\x10?"
+hla_serial "S?n\x06gePQ6G%g"
 
 tpiu config internal swodump.stm32f3-disco.log uart off 72000000