diff --git a/src/platforms/f4discovery/Makefile.inc b/src/platforms/f4discovery/Makefile.inc
index f67b278..88575bb 100644
--- a/src/platforms/f4discovery/Makefile.inc
+++ b/src/platforms/f4discovery/Makefile.inc
@@ -7,7 +7,7 @@ CFLAGS += -Istm32/include -mcpu=cortex-m4 -mthumb \
 	-DSTM32F4 -DF4DISCOVERY -I../libopencm3/include \
 	-Iplatforms/stm32
 
-LDFLAGS = -lopencm3_stm32f4 -Wl,--defsym,_stack=0x20020000 \
+LDFLAGS = -lopencm3_stm32f4 -Wl,--defsym,_stack=0x20006000 \
 	-Wl,-T,platforms/stm32/f4discovery.ld -nostartfiles -lc -lnosys \
 	-Wl,-Map=mapfile -mthumb -mcpu=cortex-m4 -Wl,-gc-sections \
 	-mfloat-abi=hard -mfpu=fpv4-sp-d16 \
diff --git a/src/platforms/f4discovery/platform.c b/src/platforms/f4discovery/platform.c
index 645a3c5..6ee36bd 100644
--- a/src/platforms/f4discovery/platform.c
+++ b/src/platforms/f4discovery/platform.c
@@ -53,7 +53,7 @@ int platform_init(void)
 		scb_reset_core();
 	}
 
-	rcc_clock_setup_hse_3v3(&hse_8mhz_3v3[CLOCK_3V3_168MHZ]);
+	rcc_clock_setup_hse_3v3(&hse_8mhz_3v3[CLOCK_3V3_48MHZ]);
 
 	/* Enable peripherals */
 	rcc_peripheral_enable_clock(&RCC_AHB2ENR, RCC_AHB2ENR_OTGFSEN);