diff --git a/ChangeLog b/ChangeLog
index 879101d2e..402614fd3 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,8 @@
 2004-10-22  Alexandre Duret-Lutz  <adl@src.lip6.fr>
 
+	* src/misc/bareword.hh, src/misc/bareword.cc (quote_unless_bare_word):
+	New function.
+
 	* src/ltlvisit/tostring.cc (to_spin_string_visitor): Move to
 	anonymous namespace.
 
diff --git a/src/misc/bareword.cc b/src/misc/bareword.cc
index 01dc784e5..3d548d797 100644
--- a/src/misc/bareword.cc
+++ b/src/misc/bareword.cc
@@ -21,6 +21,7 @@
 
 #include "bareword.hh"
 #include <ctype.h>
+#include "escape.hh"
 
 namespace spot
 {
@@ -37,4 +38,14 @@ namespace spot
 	return false;
     return true;
   }
+
+  std::string
+  quote_unless_bare_word(const std::string& str)
+  {
+    if (is_bare_word(str.c_str()))
+      return str;
+    else
+      return "\"" + escape_str(str) + "\"";
+  }
+
 }
diff --git a/src/misc/bareword.hh b/src/misc/bareword.hh
index 30c44bdf4..0c8872a91 100644
--- a/src/misc/bareword.hh
+++ b/src/misc/bareword.hh
@@ -19,7 +19,11 @@
 // Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
 // 02111-1307, USA.
 
+#include <string>
+
 namespace spot
 {
   bool is_bare_word(const char* str);
+
+  std::string quote_unless_bare_word(const std::string& str);
 }