diff --git a/bootloader.c b/bootloader.c
index 0087d5a..83a9618 100644
--- a/bootloader.c
+++ b/bootloader.c
@@ -42,11 +42,17 @@ void main(void)
 	} else { // check if the force DFU mode input is set
 		// disable SWJ pin to use as GPIO
 #if (GPIO(B)==GPIO(DFU_FORCE_PORT)) && (GPIO(4)==GPIO(DFU_FORCE_PIN))
-		gpio_primary_remap(AFIO_MAPR_SWJ_CFG_FULL_SWJ_NO_JNTRST, 0);
+		// JNTRST pin is used as DFU pin
+		rcc_periph_clock_enable(RCC_AFIO); // enable clock for alternate function domain
+		gpio_primary_remap(AFIO_MAPR_SWJ_CFG_FULL_SWJ_NO_JNTRST, 0); // keep SWJ enable bit don't use JNTRST
 #elif ((GPIO(B)==GPIO(DFU_FORCE_PORT)) && (GPIO(3)==GPIO(DFU_FORCE_PIN))) || ((GPIO(A)==GPIO(DFU_FORCE_PORT)) && (GPIO(15)==GPIO(DFU_FORCE_PIN)))
-		gpio_primary_remap(AFIO_MAPR_SWJ_CFG_JTAG_OFF_SW_ON, 0);
+		// JTAG but not SWD pin used as DFU pin
+		rcc_periph_clock_enable(RCC_AFIO); // enable clock for alternate function domain
+		gpio_primary_remap(AFIO_MAPR_SWJ_CFG_JTAG_OFF_SW_ON, 0); // disable JTAG but keep SWD
 #elif ((GPIO(A)==GPIO(DFU_FORCE_PORT)) && (GPIO(14)==GPIO(DFU_FORCE_PIN))) || ((GPIO(A)==GPIO(DFU_FORCE_PORT)) && (GPIO(13)==GPIO(DFU_FORCE_PIN)))
-		gpio_primary_remap(AFIO_MAPR_SWJ_CFG_JTAG_OFF_SW_OFF, 0);
+		// JTAG and SWD pin used as DFU pin
+		rcc_periph_clock_enable(RCC_AFIO); // enable clock for alternate function domain
+		gpio_primary_remap(AFIO_MAPR_SWJ_CFG_JTAG_OFF_SW_OFF, 0); // disable JTAG and SWD
 #endif
 		rcc_periph_clock_enable(RCC_GPIO(DFU_FORCE_PORT)); // enable clock for GPIO domain
 		gpio_set_mode(GPIO(DFU_FORCE_PORT), GPIO_MODE_INPUT, GPIO_CNF_INPUT_PULL_UPDOWN, GPIO(DFU_FORCE_PIN)); // set GPIO to input
diff --git a/global.h b/global.h
index 689e70b..e7267ee 100644
--- a/global.h
+++ b/global.h
@@ -412,10 +412,10 @@
 	#define DFU_FORCE_PIN 4 /**< GPIO pin (pin PC4) */
 	#define DFU_FORCE_VALUE 1 /**< pin floating, set high when shorted with nearby VCC */
 #else
-	/* use the JNTRST pin as GPIO (this will disable the SWJ function, but we are not using it) */
+	/* use the JNTRST pin as GPIO (SWJ will still be working, minus NTRST) */
 	#define DFU_FORCE_PORT B /**< JNTRST port (needs to be remapped to become PB4) */
 	#define DFU_FORCE_PIN 4 /**< JNTRST pin (needs to be remapped to become PB4) */
-	#define DFU_FORCE_VALUE 1 /**< must be high to force DFU mode, since it's low after reset */
+	#define DFU_FORCE_VALUE 0 /**< must be low to force DFU mode (note: JNTRST is also pulled up after reset) */
 #endif
 /** @} */