1 files changed, 2 insertions, 0 deletions
diff --git a/os/src/sprintf.c b/os/src/sprintf.c
index 76ea9a2..30d27b3 100644
--- a/os/src/sprintf.c
+++ b/os/src/sprintf.c
@@ -1,4 +1,5 @@
 #include <reent.h>
+#include <stdio.h>
 #include <stdarg.h>
 
 int sprintf(char * str, const char * fmt, ...) {
@@ -7,4 +8,5 @@ int sprintf(char * str, const char * fmt, ...) {
     va_start(ap, fmt);
     r = _vsprintf_r(_impure_ptr, str, fmt, ap);
     va_end(ap);
+    return r;
 }