diff --git a/converter/ibm4704_usb/Makefile b/converter/ibm4704_usb/Makefile
index b6adf08d..007e0e01 100644
--- a/converter/ibm4704_usb/Makefile
+++ b/converter/ibm4704_usb/Makefile
@@ -70,6 +70,10 @@ ARCH ?= AVR8
 #     CPU clock adjust registers or the clock division fuses), this will be equal to F_CPU.
 F_USB ?= $(F_CPU)
 
+# TODO: This can prevent converter ISR from handling signal instantly, better remove it.
+# Without this option debug prints from enable_break() won't be displayed comopletely.
+OPT_DEFS += -DINTERRUPT_CONTROL_ENDPOINT
+
 
 # Boot Section Size in *bytes*
 #   Teensy halfKay   512