diff --git a/src/misc/escape.cc b/src/misc/escape.cc
index f8dc32050..a10eb05c0 100644
--- a/src/misc/escape.cc
+++ b/src/misc/escape.cc
@@ -23,10 +23,6 @@
 #include "config.h"
 #include <sstream>
 #include <ostream>
-#include <algorithm>
-#include <functional>
-#include <cctype>
-#include <locale>
 #include <cstring>
 #include "escape.hh"
 
@@ -133,18 +129,6 @@ namespace spot
     return os.str();
   }
 
-  void
-  trim(std::string& str)
-  {
-    str.erase(std::find_if(str.rbegin(), str.rend(),
-			   std::not1(std::ptr_fun<int, int>
-				     (std::isspace))).base(),
-	      str.end());
-    str.erase(str.begin(),
-	      std::find_if(str.begin(), str.end(),
-			   std::not1(std::ptr_fun<int, int>(std::isspace))));
-  }
-
   std::ostream&
   quote_shell_string(std::ostream& os, const char* str)
   {
diff --git a/src/misc/escape.hh b/src/misc/escape.hh
index b3476c53a..5dff8261e 100644
--- a/src/misc/escape.hh
+++ b/src/misc/escape.hh
@@ -62,10 +62,6 @@ namespace spot
   SPOT_API std::string
   escape_str(const std::string& str);
 
-  /// \brief Remove spaces at the front and back of \a str.
-  SPOT_API void
-  trim(std::string& str);
-
   /// \brief Output \a str between simple quote or double quotes
   ///
   /// Simple quotes are preferred unless \a str contains some simple
diff --git a/src/parseaut/scanaut.ll b/src/parseaut/scanaut.ll
index 2d845912f..8687344c5 100644
--- a/src/parseaut/scanaut.ll
+++ b/src/parseaut/scanaut.ll
@@ -26,7 +26,7 @@
 #include <string>
 #include <sys/stat.h>
 #include "parseaut/parsedecl.hh"
-#include "misc/escape.hh"
+#include "priv/trim.hh"
 
 #define YY_USER_ACTION yylloc->columns(yyleng);
 #define YY_NEVER_INTERACTIVE 1
diff --git a/src/parsetl/scantl.ll b/src/parsetl/scantl.ll
index c762162ad..a1cfe66c5 100644
--- a/src/parsetl/scantl.ll
+++ b/src/parsetl/scantl.ll
@@ -31,7 +31,7 @@
 #include <string>
 
 #include "parsedecl.hh"
-#include "misc/escape.hh"
+#include "priv/trim.hh"
 
 #define YY_USER_ACTION \
   yylloc->columns(yyleng);
diff --git a/src/priv/Makefile.am b/src/priv/Makefile.am
index 7180831be..f22b13205 100644
--- a/src/priv/Makefile.am
+++ b/src/priv/Makefile.am
@@ -1,5 +1,5 @@
 ## -*- coding: utf-8 -*-
-## Copyright (C) 2013, 2014 Laboratoire de Recherche et
+## Copyright (C) 2013, 2014, 2015 Laboratoire de Recherche et
 ## Développement de l'Epita (LRDE).
 ##
 ## This file is part of Spot, a model checking library.
@@ -23,9 +23,11 @@ AM_CXXFLAGS = $(WARNING_CXXFLAGS)
 noinst_HEADERS = \
   accmap.hh \
   bddalloc.hh \
-  freelist.hh
+  freelist.hh \
+  trim.hh
 
 noinst_LTLIBRARIES = libpriv.la
 libpriv_la_SOURCES = \
   bddalloc.cc \
-  freelist.cc
+  freelist.cc \
+  trim.cc
diff --git a/src/priv/trim.cc b/src/priv/trim.cc
new file mode 100644
index 000000000..4124b1bad
--- /dev/null
+++ b/src/priv/trim.cc
@@ -0,0 +1,39 @@
+// -*- coding: utf-8 -*-
+// Copyright (C) 2015  Laboratoire de Recherche et Developpement de
+// l'Epita (LRDE).
+//
+// This file is part of Spot, a model checking library.
+//
+// Spot is free software; you can redistribute it and/or modify it
+// under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 3 of the License, or
+// (at your option) any later version.
+//
+// Spot is distributed in the hope that it will be useful, but WITHOUT
+// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+// or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
+// License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+#include "trim.hh"
+#include <algorithm>
+#include <functional>
+#include <cctype>
+#include <locale>
+
+namespace spot
+{
+  void
+  trim(std::string& str)
+  {
+    str.erase(std::find_if(str.rbegin(), str.rend(),
+			   std::not1(std::ptr_fun<int, int>
+				     (std::isspace))).base(),
+	      str.end());
+    str.erase(str.begin(),
+	      std::find_if(str.begin(), str.end(),
+			   std::not1(std::ptr_fun<int, int>(std::isspace))));
+  }
+}
diff --git a/src/priv/trim.hh b/src/priv/trim.hh
new file mode 100644
index 000000000..8073e16e8
--- /dev/null
+++ b/src/priv/trim.hh
@@ -0,0 +1,28 @@
+// -*- coding: utf-8 -*-
+// Copyright (C) 2015  Laboratoire de Recherche et Developpement de
+// l'Epita (LRDE).
+//
+// This file is part of Spot, a model checking library.
+//
+// Spot is free software; you can redistribute it and/or modify it
+// under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 3 of the License, or
+// (at your option) any later version.
+//
+// Spot is distributed in the hope that it will be useful, but WITHOUT
+// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+// or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
+// License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+#pragma once
+
+#include <string>
+
+namespace spot
+{
+  /// \brief Remove spaces at the front and back of \a str.
+  void trim(std::string& str);
+}