1 files changed, 7 insertions, 2 deletions
diff --git a/libio/iofsetpos.c b/libio/iofsetpos.c
index 72db3b1fa0..c8897522d6 100644
--- a/libio/iofsetpos.c
+++ b/libio/iofsetpos.c
@@ -30,7 +30,9 @@ _IO_fsetpos (fp, posp)
      _IO_FILE* fp;
      const _IO_fpos_t *posp;
 {
+  int result;
   CHECK_FILE (fp, EOF);
+  _IO_flockfile (fp);
   if (_IO_seekpos (fp, *posp, _IOS_INPUT|_IOS_OUTPUT) == _IO_pos_BAD)
     {
       /*ANSI explicily requires setting errno to a positive value on failure.*/
@@ -38,9 +40,12 @@ _IO_fsetpos (fp, posp)
       if (errno == 0)
 	errno = EIO;
 #endif
-      return EOF;
+      result = EOF;
     }
-  return 0;
+  else
+    result = 0;
+  _IO_funlockfile (fp);
+  return result;
 }
 
 weak_alias (_IO_fsetpos, fsetpos)