diff --git a/driver/cflexor.lex b/driver/cflexor.lex
index dd35c1fa2..526f8eaed 100644
--- a/driver/cflexor.lex
+++ b/driver/cflexor.lex
@@ -4,7 +4,7 @@
 
 %{
 /*
- * Copyright (c) 2001 Stephen Williams (steve@icarus.com)
+ * Copyright (c) 2001-2009 Stephen Williams (steve@icarus.com)
  *
  *    This source code is free software; you can redistribute it
  *    and/or modify it in source code form under the terms of the GNU
@@ -21,9 +21,6 @@
  *    along with this program; if not, write to the Free Software
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
-#ifdef HAVE_CVS_IDENT
-#ident "$Id: cflexor.lex,v 1.11 2007/03/22 16:08:18 steve Exp $"
-#endif
 
 # include  "cfparse.h"
 # include  "cfparse_misc.h"
@@ -236,3 +233,17 @@ void cfreset(FILE*fd, const char*path)
       current_file = strdup(path);
       cflloc.first_line = 1;
 }
+
+/*
+ * Modern version of flex (>=2.5.9) can clean up the scanner data.
+ */
+void destroy_lexor()
+{
+# ifdef FLEX_SCANNER
+#   if YY_FLEX_MAJOR_VERSION >= 2 && YY_FLEX_MINOR_VERSION >= 5
+#     if defined(YY_FLEX_SUBMINOR_VERSION) && YY_FLEX_SUBMINOR_VERSION >= 9
+    yylex_destroy();
+#     endif
+#   endif
+# endif
+}
diff --git a/driver/cfparse.y b/driver/cfparse.y
index 67d85db94..9ee38e7d3 100644
--- a/driver/cfparse.y
+++ b/driver/cfparse.y
@@ -1,6 +1,6 @@
 %{
 /*
- * Copyright (c) 20001 Stephen Williams (steve@icarus.com)
+ * Copyright (c) 2001-2009 Stephen Williams (steve@icarus.com)
  *
  *    This source code is free software; you can redistribute it
  *    and/or modify it in source code form under the terms of the GNU
@@ -17,10 +17,6 @@
  *    along with this program; if not, write to the Free Software
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
-#ifdef HAVE_CVS_IDENT
-#ident "$Id: cfparse.y,v 1.12 2007/04/19 02:52:53 steve Exp $"
-#endif
-
 
 # include  "globals.h"
 # include  "cfparse_misc.h"
diff --git a/driver/cfparse_misc.h b/driver/cfparse_misc.h
index b822bd7a9..708d79f93 100644
--- a/driver/cfparse_misc.h
+++ b/driver/cfparse_misc.h
@@ -1,7 +1,7 @@
 #ifndef __cfparse_misc_H
 #define __cfparse_misc_H
 /*
- * Copyright (c) 2001 Picture Elements, Inc.
+ * Copyright (c) 2001-2009 Picture Elements, Inc.
  *    Stephen Williams (steve@picturel.com)
  *
  *    This source code is free software; you can redistribute it
@@ -38,6 +38,7 @@ int cflex(void);
 int cferror(const char *);
 int cfparse(void);
 void switch_to_command_file(const char *);
+void destroy_lexor();
 char *current_file;
 
 #endif
diff --git a/driver/main.c b/driver/main.c
index d53e3ab4c..266e88df4 100644
--- a/driver/main.c
+++ b/driver/main.c
@@ -937,7 +937,9 @@ int main(int argc, char **argv)
 		  return 1;
 	    }
             free(command_filename);
+            fclose(fp);
       }
+      destroy_lexor();
 
       if (depfile) {
 	    fprintf(defines_file, "M:%s\n", depfile);