diff --git a/NEWS b/NEWS
index 846bda49d..55b5eb26d 100644
--- a/NEWS
+++ b/NEWS
@@ -59,6 +59,10 @@ New in spot 2.1.2.dev (not yet released)
     when run with use_simulation (the default) on non-simplified
     automata.
 
+  * When the automaton_stream_parser reads an automaton from an
+    already opened file descriptor, it will not close the file
+    anymore.
+
 New in spot 2.1.2 (2016-10-14)
 
   Command-line tools:
diff --git a/spot/parseaut/public.hh b/spot/parseaut/public.hh
index 259371cef..17b549b91 100644
--- a/spot/parseaut/public.hh
+++ b/spot/parseaut/public.hh
@@ -1,6 +1,6 @@
 // -*- coding: utf-8 -*-
-// Copyright (C) 2013, 2014, 2015 Laboratoire de Recherche et Développement
-// de l'Epita (LRDE).
+// Copyright (C) 2013, 2014, 2015, 2016 Laboratoire de Recherche et
+// Développement de l'Epita (LRDE).
 //
 // This file is part of Spot, a model checking library.
 //
@@ -123,7 +123,7 @@ namespace spot
     std::string filename_;
     automaton_parser_options opts_;
   public:
-    /// \brief Parse from a file opened file descriptor.
+    /// \brief Parse from a file.
     ///
     /// \param filename The file to read from.
     /// \param opts Parser options.
@@ -132,6 +132,8 @@ namespace spot
 
     /// \brief Parse from an already opened file descriptor.
     ///
+    /// The file descriptor will not be closed.
+    ///
     /// \param fd The file descriptor to read from.
     /// \param filename What to display in error messages.
     /// \param opts Parser options.
diff --git a/spot/parseaut/scanaut.ll b/spot/parseaut/scanaut.ll
index 2018b63a2..1b7b58286 100644
--- a/spot/parseaut/scanaut.ll
+++ b/spot/parseaut/scanaut.ll
@@ -38,6 +38,7 @@ static int orig_cond = 0;
 static bool lbtt_s = false;
 static bool lbtt_t = false;
 static unsigned lbtt_states = 0;
+static bool yyin_close = true;
 
 %}
 
@@ -410,15 +411,15 @@ namespace spot
 	if (S_ISFIFO(s.st_mode))
 	  want_interactive = true;
 
-	// Only set yyin once we know we will use
-	// it, so that we do not close it otherwise.
         yyin = stdin;
+        yyin_close = false;
       }
     else
       {
         yyin = fopen(name.c_str(), "r");
         if (!yyin)
 	  return 1;
+        yyin_close = true;
       }
     // Reset the lexer in case a previous parse
     // ended badly.
@@ -441,6 +442,7 @@ namespace spot
   hoayyopen(int fd)
   {
     bool want_interactive = false;
+    yyin_close = false;
 
     yyin = fdopen(fd, "r");
 
@@ -470,8 +472,9 @@ namespace spot
   {
     if (yyin)
       {
-	fclose(yyin);
-	yyin = NULL;
+        if (yyin_close)
+          fclose(yyin);
+        yyin = NULL;
       }
   }
 }