diff --git a/cpu/esp32/include/sdk_conf.h b/cpu/esp32/include/sdk_conf.h
index 5b41da079f..2440bc7524 100644
--- a/cpu/esp32/include/sdk_conf.h
+++ b/cpu/esp32/include/sdk_conf.h
@@ -89,7 +89,7 @@ extern "C" {
 #define CONFIG_SYSTEM_EVENT_TASK_STACK_SIZE     2048
 #define CONFIG_NUMBER_OF_UNIVERSAL_MAC_ADDRESS  4
 
-#define CONFIG_NEWLIB_NANO_FORMAT               0
+#define CONFIG_NEWLIB_NANO_FORMAT               1
 #define CONFIG_ESP32_DEEP_SLEEP_WAKEUP_DELAY    2000
 
 /**
diff --git a/cpu/esp32/syscalls.c b/cpu/esp32/syscalls.c
index fcbe69df16..d868fd480b 100644
--- a/cpu/esp32/syscalls.c
+++ b/cpu/esp32/syscalls.c
@@ -33,6 +33,7 @@
 #include "soc/rtc_cntl_struct.h"
 #include "soc/timer_group_reg.h"
 #include "soc/timer_group_struct.h"
+#include "sdk_conf.h"
 #include "xtensa/xtensa_api.h"
 
 #ifdef MODULE_ESP_IDF_HEAP
@@ -97,6 +98,18 @@ static int _no_sys_func(struct _reent *r)
     return -1;
 }
 
+extern int _printf_float(struct _reent *rptr,
+                         void *pdata,
+                         FILE * fp,
+                         int (*pfunc) (struct _reent *, FILE *,
+                                       _CONST char *, size_t len),
+                         va_list * ap);
+
+extern int _scanf_float(struct _reent *rptr,
+                        void *pdata,
+                        FILE *fp,
+                        va_list *ap);
+
 static struct syscall_stub_table s_stub_table =
 {
     .__getreent = &__getreent,