diff --git a/boards/stm32f3discovery/include/periph_conf.h b/boards/stm32f3discovery/include/periph_conf.h
index 79bd8cad5b4c32756605c34370280064e289cd92..bf7105bac91e6df64d6d14f36bc76f0399dd3a80 100644
--- a/boards/stm32f3discovery/include/periph_conf.h
+++ b/boards/stm32f3discovery/include/periph_conf.h
@@ -40,7 +40,7 @@ extern "C" {
 #define CLOCK_HSE           (8000000U)
 /* 0: no external low speed crystal available,
  * 1: external crystal available (always 32.768kHz) */
-#define CLOCK_LSE           (1)
+#define CLOCK_LSE           (0)
 /* peripheral clock setup */
 #define CLOCK_AHB_DIV       RCC_CFGR_HPRE_DIV1
 #define CLOCK_AHB           (CLOCK_CORECLOCK / 1)