diff --git a/stm-firmware/syscalls.c b/stm-firmware/syscalls.c
index 1747e47..d8fff8a 100644
--- a/stm-firmware/syscalls.c
+++ b/stm-firmware/syscalls.c
@@ -1,41 +1,64 @@
 #include <stm-periph/uart.h>
 
-char* _sbrk(int incr) {
-            extern char heap_low;    // Defined by the linker
-            extern char heap_top;
-            static char *heap_end;
-            char *prev_heap_end;
+char* _sbrk(int incr)
+{
+	extern char heap_low;    // Defined by the linker
+	extern char heap_top;
+	static char *heap_end;
+	char *prev_heap_end;
 
-            if (heap_end == 0) {
-              heap_end = &heap_low;
-            }
-            prev_heap_end = heap_end;
-            if (heap_end + incr > &heap_top) {
-              return 0;
-            }
+	if (heap_end == 0) {
+		heap_end = &heap_low;
+	}
+
+	prev_heap_end = heap_end;
+	if (heap_end + incr > &heap_top) {
+		return 0;
+	}
+
+	heap_end += incr;
+	return (char*) prev_heap_end;
+}
+
+int _isatty(int fd)
+{
+	(void)fd;
 
-            heap_end += incr;
-            return (char*) prev_heap_end;
-          }
-int _isatty(int fd) {
 	return 1;
 }
-int _close(int fd) {
+
+int _close(int fd)
+{
+	(void)fd;
+
 	return 0;
 }
-int _open(int fd) {
+
+int _open(int fd)
+{
+	(void)fd;
+
 	return 0;
 }
-int _fstat(void) {
+
+int _fstat(void)
+{
 	return 0;
 }
-int _lseek(void) {
+
+int _lseek(void)
+{
 	return 0;
 }
-int _read(void) {
+
+int _read(void)
+{
 	return 0;
 }
-int _write(int fd, const void *buf, int count) {
-	uart_send_array((char*)buf, count);
+
+int _write(int fd, const void *buf, int count)
+{
+	if (fd == 1)
+		uart_send_array((char*)buf, count);
 	return count;
 }