diff --git a/GRRLIB/GRRLIB/GRRLIB_gecko.c b/GRRLIB/GRRLIB/GRRLIB_gecko.c
index ed4587c..3082c50 100644
--- a/GRRLIB/GRRLIB/GRRLIB_gecko.c
+++ b/GRRLIB/GRRLIB/GRRLIB_gecko.c
@@ -57,7 +57,7 @@ void  GRRLIB_GeckoPrintf (const char *text, ...) {
 
     va_list argp;
     va_start(argp, text);
-    size = vsprintf(tmp, text, argp);
+    size = vsnprintf(tmp, sizeof(tmp), text, argp);
     va_end(argp);
 
     usb_sendbuffer_safe(1, tmp, size);
diff --git a/GRRLIB/GRRLIB/GRRLIB_print.c b/GRRLIB/GRRLIB/GRRLIB_print.c
index 1a98558..73b8bff 100644
--- a/GRRLIB/GRRLIB/GRRLIB_print.c
+++ b/GRRLIB/GRRLIB/GRRLIB_print.c
@@ -78,7 +78,7 @@ void  GRRLIB_PrintBMF (const f32 xpos, const f32 ypos,
 
     va_list argp;
     va_start(argp, text);
-    size = vsprintf(tmp, text, argp);
+    size = vsnprintf(tmp, sizeof(tmp), text, argp);
     va_end(argp);
 
     for (i=0; i<size; i++) {