diff --git a/check.t b/check.t
index e1841b4..f7d91bc 100644
--- a/check.t
+++ b/check.t
@@ -1,4 +1,4 @@
-# $MirOS: src/bin/mksh/check.t,v 1.725 2016/02/26 22:03:10 tg Exp $
+# $MirOS: src/bin/mksh/check.t,v 1.726 2016/03/01 18:30:01 tg Exp $
 # -*- mode: sh -*-
 #-
 # Copyright © 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010,
@@ -30,7 +30,7 @@
 # (2013/12/02 20:39:44) http://openbsd.cs.toronto.edu/cgi-bin/cvsweb/src/regress/bin/ksh/?sortby=date
 
 expected-stdout:
-	@(#)MIRBSD KSH R52 2016/02/26
+	@(#)MIRBSD KSH R52 2016/03/01
 description:
 	Check version of shell.
 stdin:
@@ -39,7 +39,7 @@ name: KSH_VERSION
 category: shell:legacy-no
 ---
 expected-stdout:
-	@(#)LEGACY KSH R52 2016/02/26
+	@(#)LEGACY KSH R52 2016/03/01
 description:
 	Check version of legacy shell.
 stdin:
@@ -2249,7 +2249,7 @@ expected-stdout:
 	hi
 	there
 ---
-name: heredoc-4
+name: heredoc-4a
 description:
 	Check that an error occurs if the heredoc-delimiter is missing.
 stdin: !
@@ -2259,6 +2259,34 @@ stdin: !
 expected-exit: e > 0
 expected-stderr-pattern: /.*/
 ---
+name: heredoc-4an
+description:
+	Check that an error occurs if the heredoc-delimiter is missing.
+arguments: !-n!
+stdin: !
+	cat << EOF
+	hi
+	there
+expected-exit: e > 0
+expected-stderr-pattern: /.*/
+---
+name: heredoc-4b
+description:
+	Check that an error occurs if the heredoc is missing.
+stdin: !
+	cat << EOF
+expected-exit: e > 0
+expected-stderr-pattern: /.*/
+---
+name: heredoc-4bn
+description:
+	Check that an error occurs if the heredoc is missing.
+arguments: !-n!
+stdin: !
+	cat << EOF
+expected-exit: e > 0
+expected-stderr-pattern: /.*/
+---
 name: heredoc-5
 description:
 	Check that backslash quotes a $, ` and \ and kills a \newline
diff --git a/exec.c b/exec.c
index c542ec4..b7cdbd1 100644
--- a/exec.c
+++ b/exec.c
@@ -23,7 +23,7 @@
 
 #include "sh.h"
 
-__RCSID("$MirOS: src/bin/mksh/exec.c,v 1.171 2016/01/21 18:24:39 tg Exp $");
+__RCSID("$MirOS: src/bin/mksh/exec.c,v 1.172 2016/03/01 18:30:04 tg Exp $");
 
 #ifndef MKSH_DEFAULT_EXECSHELL
 #define MKSH_DEFAULT_EXECSHELL	MKSH_UNIXROOT "/bin/sh"
@@ -1581,13 +1581,6 @@ herein(struct ioword *iop, char **resbuf)
 	struct temp *h;
 	int i;
 
-	/* ksh -c 'cat <<EOF' can cause this... */
-	if (iop->heredoc == NULL && !(iop->ioflag & IOHERESTR)) {
-		warningf(true, Tmissinghere);
-		/* special to iosetup(): don't print error */
-		return (-2);
-	}
-
 	/* lexer substitution flags */
 	i = (iop->ioflag & IOEVAL) ? (ONEWORD | HEREDOC) : 0;
 
diff --git a/lex.c b/lex.c
index e0bc0d9..2dd71dd 100644
--- a/lex.c
+++ b/lex.c
@@ -23,7 +23,7 @@
 
 #include "sh.h"
 
-__RCSID("$MirOS: src/bin/mksh/lex.c,v 1.220 2016/03/01 18:00:08 tg Exp $");
+__RCSID("$MirOS: src/bin/mksh/lex.c,v 1.221 2016/03/01 18:30:04 tg Exp $");
 
 /*
  * states while lexing word
@@ -1000,6 +1000,16 @@ yylex(int cf)
 				if (cf & CONTIN)
 					goto Again;
 			}
+		} else if (c == '\0' && !(cf & HEREDELIM)) {
+			struct ioword **p = heres;
+
+			while (p < herep)
+				if ((*p)->ioflag & IOHERESTR)
+					++p;
+				else
+					/* ksh -c 'cat <<EOF' can cause this */
+					yyerror("here document '%s' unclosed\n",
+					    evalstr((*p)->delim, 0));
 		}
 		return (c);
 	}
@@ -1173,7 +1183,7 @@ readhere(struct ioword *iop)
 	while (c != '\n') {
 		if (!c)
 			/* oops, reached EOF */
-			yyerror("%s '%s' unclosed\n", Theredoc, eof);
+			yyerror("here document '%s' unclosed\n", eof);
 		/* store character */
 		Xcheck(xs, xp);
 		Xput(xs, xp, c);
diff --git a/sh.h b/sh.h
index 59299ea..11a8dc8 100644
--- a/sh.h
+++ b/sh.h
@@ -175,9 +175,9 @@
 #endif
 
 #ifdef EXTERN
-__RCSID("$MirOS: src/bin/mksh/sh.h,v 1.765 2016/02/26 21:53:37 tg Exp $");
+__RCSID("$MirOS: src/bin/mksh/sh.h,v 1.766 2016/03/01 18:30:05 tg Exp $");
 #endif
-#define MKSH_VERSION "R52 2016/02/26"
+#define MKSH_VERSION "R52 2016/03/01"
 
 /* arithmetic types: C implementation */
 #if !HAVE_CAN_INTTYPES
@@ -887,12 +887,6 @@ EXTERN const char T_funny_command[] E_INIT("funny $() command");
 EXTERN const char Tfg_badsubst[] E_INIT("fileglob: bad substitution");
 #endif
 #define Tbadsubst	(Tfg_badsubst + 10)	/* "bad substitution" */
-#if defined(__GNUC__)
-#define Tmissinghere	"missing here document"
-#else
-EXTERN const char Tmissinghere[] E_INIT("missing here document");
-#endif
-#define Theredoc	(Tmissinghere + 8)	/* "here document" */
 EXTERN const char TC_LEX1[] E_INIT("|&;<>() \t\n");
 #define TC_IFSWS	(TC_LEX1 + 7)		/* space tab newline */