diff --git a/py/objcomplex.c b/py/objcomplex.c
index af148a2786..24762e8b11 100644
--- a/py/objcomplex.c
+++ b/py/objcomplex.c
@@ -24,9 +24,9 @@ mp_obj_t mp_obj_new_complex(mp_float_t real, mp_float_t imag);
 void complex_print(void (*print)(void *env, const char *fmt, ...), void *env, mp_obj_t o_in, mp_print_kind_t kind) {
     mp_obj_complex_t *o = o_in;
     if (o->real == 0) {
-        print(env, "%.8gj", o->imag);
+        print(env, "%.8gj",  (double) o->imag);
     } else {
-        print(env, "(%.8g+%.8gj)", o->real, o->imag);
+        print(env, "(%.8g+%.8gj)", (double) o->real, (double) o->imag);
     }
 }
 
diff --git a/py/objfloat.c b/py/objfloat.c
index 9f1f478cab..69fd65e199 100644
--- a/py/objfloat.c
+++ b/py/objfloat.c
@@ -21,7 +21,7 @@ mp_obj_t mp_obj_new_float(mp_float_t value);
 
 static void float_print(void (*print)(void *env, const char *fmt, ...), void *env, mp_obj_t o_in, mp_print_kind_t kind) {
     mp_obj_float_t *o = o_in;
-    print(env, "%.8g", o->value);
+    print(env, "%.8g", (double) o->value);
 }
 
 static mp_obj_t float_make_new(mp_obj_t type_in, uint n_args, uint n_kw, const mp_obj_t *args) {
diff --git a/stm/lcd.c b/stm/lcd.c
index dae4157a46..6f5019db1b 100644
--- a/stm/lcd.c
+++ b/stm/lcd.c
@@ -41,6 +41,16 @@
 #define PYB_LCD_BL_PORT    (GPIOB)
 #define PYB_LCD_BL_PIN     (GPIO_Pin_1) // Y12 = PB1
 */
+#elif defined(STM32F4DISC)
+/* Configure if needed */
+#define PYB_LCD_PORT       (GPIOA)
+#define PYB_LCD_CS1_PIN    (GPIO_Pin_2) // X3
+#define PYB_LCD_RST_PIN    (GPIO_Pin_3) // X4
+#define PYB_LCD_A0_PIN     (GPIO_Pin_4) // X5
+#define PYB_LCD_SCL_PIN    (GPIO_Pin_5) // X6
+#define PYB_LCD_SI_PIN     (GPIO_Pin_7) // X8
+#define PYB_LCD_BL_PORT    (GPIOC)
+#define PYB_LCD_BL_PIN     (GPIO_Pin_5) // X12
 #endif
 
 #define LCD_INSTR (0)
diff --git a/stm/printf.c b/stm/printf.c
index 82b168d1c4..2669a55344 100644
--- a/stm/printf.c
+++ b/stm/printf.c
@@ -6,6 +6,7 @@
 #include "misc.h"
 #include "systick.h"
 #include "mpconfig.h"
+#include "mpconfigport.h"
 #include "qstr.h"
 #include "obj.h"
 #include "lcd.h"
@@ -247,7 +248,9 @@ void stdout_print_strn(void *data, const char *str, unsigned int len) {
         any = true;
     }
     if (!any) {
+#if MICROPY_HW_HAS_LCD
         lcd_print_strn(str, len);
+#endif
     }
 }