1 files changed, 3 insertions, 1 deletions
diff --git a/libio/vsnprintf.c b/libio/vsnprintf.c
index 174640daac..9f767b5b06 100644
--- a/libio/vsnprintf.c
+++ b/libio/vsnprintf.c
@@ -33,9 +33,11 @@ _IO_vsnprintf (string, maxlen, format, args)
      _IO_va_list args;
 {
   _IO_strfile sf;
-  _IO_lock_t lock;
   int ret;
+#ifdef _IO_MTSAFE_IO
+  _IO_lock_t lock;
   sf._f._lock = &lock;
+#endif
   _IO_init ((_IO_FILE *) &sf, 0);
   _IO_JUMPS ((_IO_FILE *) &sf) = &_IO_str_jumps;
   _IO_str_init_static ((_IO_FILE *) &sf, string, maxlen - 1, string);