diff --git a/misc/io_utils.c b/misc/io_utils.c
index fafed772cc..777e1c780c 100644
--- a/misc/io_utils.c
+++ b/misc/io_utils.c
@@ -45,7 +45,7 @@ int mp_mkostemps(char *template, int suffixlen, int flags)
         // not truly random; just a counter would be sufficient).
         size_t fuckmess = mp_rand_next();
         char crap[7] = "";
-        snprintf(crap, sizeof(crap), "%06zx", fuckmess);
+        mp_tprintf_buf(crap, sizeof(crap), "%06zx", fuckmess);
         memcpy(t, crap, 6);
 
         int res = open(template, O_RDWR | O_CREAT | O_EXCL | flags, 0600);
diff --git a/osdep/windows_utils.c b/osdep/windows_utils.c
index 91eef62cb8..2befea2d86 100644
--- a/osdep/windows_utils.c
+++ b/osdep/windows_utils.c
@@ -143,9 +143,9 @@ static char *fmtmsg_buf(char *buf, size_t buf_size, DWORD errorID)
                              FORMAT_MESSAGE_IGNORE_INSERTS,
                              NULL, errorID, 0, buf, buf_size, NULL);
     if (!n && GetLastError() == ERROR_MORE_DATA) {
-        snprintf(buf, buf_size,
-                 "<Insufficient buffer size (%zd) for error message>",
-                 buf_size);
+        mp_tprintf_buf(buf, buf_size,
+                       "<Insufficient buffer size (%zd) for error message>",
+                       buf_size);
     } else {
         if (n > 0 && buf[n-1] == '\n')
             buf[n-1] = '\0';