diff --git a/usr.bin/lex/initparse.h b/usr.bin/lex/initparse.h
--- a/usr.bin/lex/initparse.h
+++ b/usr.bin/lex/initparse.h
@@ -1,4 +1,3 @@
-/* $FreeBSD$ */
 #define CHAR 257
 #define NUMBER 258
 #define SECTEND 259
diff --git a/usr.bin/lex/initparse.c b/usr.bin/lex/initparse.c
--- a/usr.bin/lex/initparse.c
+++ b/usr.bin/lex/initparse.c
@@ -1,4 +1,3 @@
-/* $FreeBSD$ */
 /* original parser id follows */
 /* yysccsid[] = "@(#)yaccpar	1.9 (Berkeley) 02/21/93" */
 /* (use YYMAJOR/YYMINOR for ifdefs dependent on parser version) */
@@ -6,7 +5,7 @@
 #define YYBYACC 1
 #define YYMAJOR 1
 #define YYMINOR 9
-#define YYPATCH 20170430
+#define YYPATCH 20200330
 
 #define YYEMPTY        (-1)
 #define yyclearin      (yychar = YYEMPTY)
@@ -19,8 +18,6 @@
 #define YYPURE 0
 
 #line 35 "parse.y"
-/* SPDX-License-Identifier: BSD-2-Clause */
-
 /*  Copyright (c) 1990 The Regents of the University of California. */
 /*  All rights reserved. */
 
@@ -130,6 +127,10 @@
 # define YYLEX yylex()
 #endif
 
+#if !(defined(yylex) || defined(YYSTATE))
+int YYLEX_DECL();
+#endif
+
 /* Parameters sent to yyerror. */
 #ifndef YYERROR_DECL
 #define YYERROR_DECL() yyerror(const char *s)
@@ -488,13 +489,15 @@
 };
 #endif
 
+#if YYDEBUG
 int      yydebug;
-int      yynerrs;
+#endif
 
 int      yyerrflag;
 int      yychar;
 YYSTYPE  yyval;
 YYSTYPE  yylval;
+int      yynerrs;
 
 /* define the initial stack-sizes */
 #ifdef YYSTACKSIZE
@@ -655,7 +658,7 @@
 	{
 		(void)msg;
 	}
-#line 656 "parse.c"
+#line 662 "parse.c"
 
 #if YYDEBUG
 #include <stdio.h>	/* needed for printf */
@@ -1781,7 +1784,7 @@
 #line 946 "parse.y"
 	{ yyval = mkstate( SYM_EPSILON ); }
 break;
-#line 1782 "parse.c"
+#line 1788 "parse.c"
     }
     yystack.s_mark -= yym;
     yystate = *yystack.s_mark;
diff --git a/usr.bin/lex/initscan.c b/usr.bin/lex/initscan.c
--- a/usr.bin/lex/initscan.c
+++ b/usr.bin/lex/initscan.c
@@ -1,4 +1,3 @@
-/* $FreeBSD$ */
 
 #line 2 "<stdout>"
 
@@ -4578,7 +4577,11 @@
 				case EOB_ACT_END_OF_FILE:
 					{
 					if ( yywrap(  ) )
+#ifdef YY_FLEX_LEX_COMPAT
 						return 0;
+#else
+						return EOF;
+#endif
 
 					if ( ! (yy_did_buffer_switch_on_eof) )
 						YY_NEW_FILE;
diff --git a/usr.bin/lex/initskel.c b/usr.bin/lex/initskel.c
--- a/usr.bin/lex/initskel.c
+++ b/usr.bin/lex/initskel.c
@@ -1,4 +1,3 @@
-/* $FreeBSD$ */
 /* File created from flex.skl via mkskel.sh */
 
 #include "flexdef.h"
@@ -448,11 +447,7 @@
   "/* First, we deal with  platform-specific or compiler-specific issues. */",
   "",
   "#if defined(__FreeBSD__)",
-  "#ifndef __STDC_LIMIT_MACROS",
-  "#define	__STDC_LIMIT_MACROS",
-  "#endif",
   "#include <sys/cdefs.h>",
-  "#include <stdint.h>",
   "#else",
   "#define	__dead2",
   "#endif",
@@ -2301,7 +2296,11 @@
   "				case EOB_ACT_END_OF_FILE:",
   "					{",
   "					if ( yywrap( M4_YY_CALL_ONLY_ARG ) )",
+  "#ifdef YY_FLEX_LEX_COMPAT",
   "						return 0;",
+  "#else",
+  "						return EOF;",
+  "#endif",
   "",
   "					if ( ! YY_G(yy_did_buffer_switch_on_eof) )",
   "						YY_NEW_FILE;",