diff --git a/src/option.c b/src/option.c
index bfdf717..8e62efc 100644
--- a/src/option.c
+++ b/src/option.c
@@ -467,6 +467,7 @@
 				  * there is a redraw flag */
 #define P_NDNAME      0x8000000L /* only normal dir name chars allowed */
 #define P_RWINONLY   0x10000000L /* only redraw current window */
+#define P_MLE	     0x20000000L /* under control of 'modelineexpr' */
 
 #define ISK_LATIN1  (char_u *)"@,48-57,_,192-255"
 
@@ -650,7 +651,7 @@
 			    {(char_u *)0L, (char_u *)0L}
 #endif
 			    SCTX_INIT},
-    {"balloonexpr", "bexpr", P_STRING|P_ALLOCED|P_VI_DEF|P_VIM,
+    {"balloonexpr", "bexpr", P_STRING|P_ALLOCED|P_VI_DEF|P_VIM|P_MLE,
 #if defined(FEAT_BEVAL) && defined(FEAT_EVAL)
 			    (char_u *)&p_bexpr, PV_BEXPR,
 			    {(char_u *)"", (char_u *)0L}
@@ -727,7 +728,7 @@
 			    (char_u *)&p_cmp, PV_NONE,
 			    {(char_u *)"internal,keepascii", (char_u *)0L}
 			    SCTX_INIT},
-    {"cdpath",	    "cd",   P_STRING|P_EXPAND|P_VI_DEF|P_COMMA|P_NODUP,
+    {"cdpath",	    "cd",   P_STRING|P_EXPAND|P_VI_DEF|P_SECURE|P_COMMA|P_NODUP,
 #ifdef FEAT_SEARCHPATH
 			    (char_u *)&p_cdpath, PV_NONE,
 			    {(char_u *)",,", (char_u *)0L}
@@ -1175,7 +1176,7 @@
 			    {(char_u *)NULL, (char_u *)0L}
 #endif
 			    SCTX_INIT},
-    {"foldexpr",    "fde",  P_STRING|P_ALLOCED|P_VIM|P_VI_DEF|P_RWIN,
+    {"foldexpr",    "fde",  P_STRING|P_ALLOCED|P_VIM|P_VI_DEF|P_RWIN|P_MLE,
 #if defined(FEAT_FOLDING) && defined(FEAT_EVAL)
 			    (char_u *)VAR_WIN, PV_FDE,
 			    {(char_u *)"0", (char_u *)NULL}
@@ -1258,7 +1259,7 @@
 			    {(char_u *)NULL, (char_u *)0L}
 #endif
 			    SCTX_INIT},
-    {"foldtext",    "fdt",  P_STRING|P_ALLOCED|P_VIM|P_VI_DEF|P_RWIN,
+    {"foldtext",    "fdt",  P_STRING|P_ALLOCED|P_VIM|P_VI_DEF|P_RWIN|P_MLE,
 #if defined(FEAT_FOLDING) && defined(FEAT_EVAL)
 			    (char_u *)VAR_WIN, PV_FDT,
 			    {(char_u *)"foldtext()", (char_u *)NULL}
@@ -1267,7 +1268,7 @@
 			    {(char_u *)NULL, (char_u *)0L}
 #endif
 			    SCTX_INIT},
-    {"formatexpr", "fex",   P_STRING|P_ALLOCED|P_VI_DEF|P_VIM,
+    {"formatexpr", "fex",   P_STRING|P_ALLOCED|P_VI_DEF|P_VIM|P_MLE,
 #ifdef FEAT_EVAL
 			    (char_u *)&p_fex, PV_FEX,
 			    {(char_u *)"", (char_u *)0L}
@@ -1406,7 +1407,7 @@
 			    (char_u *)NULL, PV_NONE,
 #endif
 			    {(char_u *)TRUE, (char_u *)0L} SCTX_INIT},
-    {"guitablabel",  "gtl", P_STRING|P_VI_DEF|P_RWIN,
+    {"guitablabel",  "gtl", P_STRING|P_VI_DEF|P_RWIN|P_MLE,
 #if defined(FEAT_GUI_TABLINE)
 			    (char_u *)&p_gtl, PV_NONE,
 			    {(char_u *)"", (char_u *)0L}
@@ -1477,7 +1478,7 @@
 			    (char_u *)NULL, PV_NONE,
 #endif
 			    {(char_u *)FALSE, (char_u *)0L} SCTX_INIT},
-    {"iconstring",  NULL,   P_STRING|P_VI_DEF,
+    {"iconstring",  NULL,   P_STRING|P_VI_DEF|P_MLE,
 #ifdef FEAT_TITLE
 			    (char_u *)&p_iconstring, PV_NONE,
 #else
@@ -1549,7 +1550,7 @@
 			    {(char_u *)0L, (char_u *)0L}
 #endif
 			    SCTX_INIT},
-    {"includeexpr", "inex", P_STRING|P_ALLOCED|P_VI_DEF,
+    {"includeexpr", "inex", P_STRING|P_ALLOCED|P_VI_DEF|P_MLE,
 #if defined(FEAT_FIND_ID) && defined(FEAT_EVAL)
 			    (char_u *)&p_inex, PV_INEX,
 			    {(char_u *)"", (char_u *)0L}
@@ -1561,7 +1562,7 @@
     {"incsearch",   "is",   P_BOOL|P_VI_DEF|P_VIM,
 			    (char_u *)&p_is, PV_NONE,
 			    {(char_u *)FALSE, (char_u *)0L} SCTX_INIT},
-    {"indentexpr", "inde",  P_STRING|P_ALLOCED|P_VI_DEF|P_VIM,
+    {"indentexpr", "inde",  P_STRING|P_ALLOCED|P_VI_DEF|P_VIM|P_MLE,
 #if defined(FEAT_CINDENT) && defined(FEAT_EVAL)
 			    (char_u *)&p_inde, PV_INDE,
 			    {(char_u *)"", (char_u *)0L}
@@ -1888,6 +1889,9 @@
     {"modeline",    "ml",   P_BOOL|P_VIM,
 			    (char_u *)&p_ml, PV_ML,
 			    {(char_u *)FALSE, (char_u *)TRUE} SCTX_INIT},
+    {"modelineexpr", "mle",  P_BOOL|P_VI_DEF,
+			    (char_u *)&p_mle, PV_NONE,
+			    {(char_u *)FALSE, (char_u *)0L} SCTX_INIT},
     {"modelines",   "mls",  P_NUM|P_VI_DEF,
 			    (char_u *)&p_mls, PV_NONE,
 			    {(char_u *)5L, (char_u *)0L} SCTX_INIT},
@@ -2311,7 +2315,7 @@
 			    (char_u *)NULL, PV_NONE,
 #endif
 			    {(char_u *)FALSE, (char_u *)0L} SCTX_INIT},
-    {"rulerformat", "ruf",  P_STRING|P_VI_DEF|P_ALLOCED|P_RSTAT,
+    {"rulerformat", "ruf",  P_STRING|P_VI_DEF|P_ALLOCED|P_RSTAT|P_MLE,
 #ifdef FEAT_STL_OPT
 			    (char_u *)&p_ruf, PV_NONE,
 #else
@@ -2577,7 +2581,7 @@
     {"startofline", "sol",  P_BOOL|P_VI_DEF|P_VIM,
 			    (char_u *)&p_sol, PV_NONE,
 			    {(char_u *)TRUE, (char_u *)0L} SCTX_INIT},
-    {"statusline"  ,"stl",  P_STRING|P_VI_DEF|P_ALLOCED|P_RSTAT,
+    {"statusline"  ,"stl",  P_STRING|P_VI_DEF|P_ALLOCED|P_RSTAT|P_MLE,
 #ifdef FEAT_STL_OPT
 			    (char_u *)&p_stl, PV_STL,
 #else
@@ -2624,7 +2628,7 @@
 			    {(char_u *)0L, (char_u *)0L}
 #endif
 			    SCTX_INIT},
-    {"tabline",	    "tal",  P_STRING|P_VI_DEF|P_RALL,
+    {"tabline",	    "tal",  P_STRING|P_VI_DEF|P_RALL|P_MLE,
 #ifdef FEAT_STL_OPT
 			    (char_u *)&p_tal, PV_NONE,
 #else
@@ -2802,7 +2806,7 @@
 			    {(char_u *)0L, (char_u *)0L}
 #endif
 			    SCTX_INIT},
-    {"titlestring", NULL,   P_STRING|P_VI_DEF,
+    {"titlestring", NULL,   P_STRING|P_VI_DEF|P_MLE,
 #ifdef FEAT_TITLE
 			    (char_u *)&p_titlestring, PV_NONE,
 #else
@@ -4549,6 +4553,11 @@
 		    errmsg = _("E520: Not allowed in a modeline");
 		    goto skip;
 		}
+		if ((flags & P_MLE) && !p_mle)
+		{
+		    errmsg = _("E992: Not allowed in a modeline when 'modelineexpr' is off");
+		    goto skip;
+		}
 #ifdef FEAT_DIFF
 		/* In diff mode some options are overruled.  This avoids that
 		 * 'foldmethod' becomes "marker" instead of "diff" and that
diff --git a/src/option.h b/src/option.h
index 7a10bb9..082ff9b 100644
--- a/src/option.h
+++ b/src/option.h
@@ -631,6 +631,7 @@
 #ifdef FEAT_SPELL
 EXTERN char_u	*p_msm;		/* 'mkspellmem' */
 #endif
+EXTERN long	p_mle;		/* 'modelineexpr' */
 EXTERN long	p_mls;		/* 'modelines' */
 EXTERN char_u	*p_mouse;	/* 'mouse' */
 #ifdef FEAT_GUI
diff --git a/src/testdir/test49.in b/src/testdir/test49.in
index 79f13f6..a0c9e0d 100644
--- a/src/testdir/test49.in
+++ b/src/testdir/test49.in
@@ -5,7 +5,7 @@
 
 STARTTEST
 :so small.vim
-:se nocp nomore viminfo+=nviminfo
+:se nocp nomore viminfo+=nviminfo modelineexpr
 :lang mess C
 :so test49.vim
 :" Go back to this file and append the results from register r.
diff --git a/src/testdir/test_modeline.vim b/src/testdir/test_modeline.vim
index e0f97c4..c33a080 100644
--- a/src/testdir/test_modeline.vim
+++ b/src/testdir/test_modeline.vim
@@ -60,14 +60,17 @@
   set keymap= iminsert=0 imsearch=-1
 endfunc
 
-func s:modeline_fails(what, text)
+func s:modeline_fails(what, text, error)
+  if !exists('+' .. a:what)
+    return
+  endif
   let fname = "Xmodeline_fails_" . a:what
   call writefile(['vim: set ' . a:text . ' :', 'nothing'], fname)
   let modeline = &modeline
   set modeline
   filetype plugin on
   syntax enable
-  call assert_fails('split ' . fname, 'E474:')
+  call assert_fails('split ' . fname, a:error)
   call assert_equal("", &filetype)
   call assert_equal("", &syntax)
 
@@ -79,16 +82,90 @@
 endfunc
 
 func Test_modeline_filetype_fails()
-  call s:modeline_fails('filetype', 'ft=evil$CMD')
+  call s:modeline_fails('filetype', 'ft=evil$CMD', 'E474:')
 endfunc
 
 func Test_modeline_syntax_fails()
-  call s:modeline_fails('syntax', 'syn=evil$CMD')
+  call s:modeline_fails('syntax', 'syn=evil$CMD', 'E474:')
 endfunc
 
 func Test_modeline_keymap_fails()
-  if !has('keymap')
-    return
-  endif
-  call s:modeline_fails('keymap', 'keymap=evil$CMD')
+  call s:modeline_fails('keymap', 'keymap=evil$CMD', 'E474:')
+endfunc
+
+func Test_modeline_fails_always()
+  call s:modeline_fails('backupdir', 'backupdir=Something()', 'E520:')
+  call s:modeline_fails('cdpath', 'cdpath=Something()', 'E520:')
+  call s:modeline_fails('charconvert', 'charconvert=Something()', 'E520:')
+  call s:modeline_fails('completefunc', 'completefunc=Something()', 'E520:')
+  call s:modeline_fails('cscopeprg', 'cscopeprg=Something()', 'E520:')
+  call s:modeline_fails('diffexpr', 'diffexpr=Something()', 'E520:')
+  call s:modeline_fails('directory', 'directory=Something()', 'E520:')
+  call s:modeline_fails('equalprg', 'equalprg=Something()', 'E520:')
+  call s:modeline_fails('errorfile', 'errorfile=Something()', 'E520:')
+  call s:modeline_fails('exrc', 'exrc=Something()', 'E520:')
+  call s:modeline_fails('formatprg', 'formatprg=Something()', 'E520:')
+  call s:modeline_fails('fsync', 'fsync=Something()', 'E520:')
+  call s:modeline_fails('grepprg', 'grepprg=Something()', 'E520:')
+  call s:modeline_fails('helpfile', 'helpfile=Something()', 'E520:')
+  call s:modeline_fails('imactivatefunc', 'imactivatefunc=Something()', 'E520:')
+  call s:modeline_fails('imstatusfunc', 'imstatusfunc=Something()', 'E520:')
+  call s:modeline_fails('imstyle', 'imstyle=Something()', 'E520:')
+  call s:modeline_fails('keywordprg', 'keywordprg=Something()', 'E520:')
+  call s:modeline_fails('langmap', 'langmap=Something()', 'E520:')
+  call s:modeline_fails('luadll', 'luadll=Something()', 'E520:')
+  call s:modeline_fails('makeef', 'makeef=Something()', 'E520:')
+  call s:modeline_fails('makeprg', 'makeprg=Something()', 'E520:')
+  call s:modeline_fails('makespellmem', 'makespellmem=Something()', 'E520:')
+  call s:modeline_fails('mzschemedll', 'mzschemedll=Something()', 'E520:')
+  call s:modeline_fails('mzschemegcdll', 'mzschemegcdll=Something()', 'E520:')
+  call s:modeline_fails('omnifunc', 'omnifunc=Something()', 'E520:')
+  call s:modeline_fails('operatorfunc', 'operatorfunc=Something()', 'E520:')
+  call s:modeline_fails('perldll', 'perldll=Something()', 'E520:')
+  call s:modeline_fails('printdevice', 'printdevice=Something()', 'E520:')
+  call s:modeline_fails('patchexpr', 'patchexpr=Something()', 'E520:')
+  call s:modeline_fails('printexpr', 'printexpr=Something()', 'E520:')
+  call s:modeline_fails('pythondll', 'pythondll=Something()', 'E520:')
+  call s:modeline_fails('pythonhome', 'pythondll=Something()', 'E520:')
+  call s:modeline_fails('pythonthreedll', 'pythonthreedll=Something()', 'E520:')
+  call s:modeline_fails('pythonthreehome', 'pythonthreehome=Something()', 'E520:')
+  call s:modeline_fails('pyxversion', 'pyxversion=Something()', 'E520:')
+  call s:modeline_fails('rubydll', 'rubydll=Something()', 'E520:')
+  call s:modeline_fails('runtimepath', 'runtimepath=Something()', 'E520:')
+  call s:modeline_fails('secure', 'secure=Something()', 'E520:')
+  call s:modeline_fails('shell', 'shell=Something()', 'E520:')
+  call s:modeline_fails('shellcmdflag', 'shellcmdflag=Something()', 'E520:')
+  call s:modeline_fails('shellpipe', 'shellpipe=Something()', 'E520:')
+  call s:modeline_fails('shellquote', 'shellquote=Something()', 'E520:')
+  call s:modeline_fails('shellredir', 'shellredir=Something()', 'E520:')
+  call s:modeline_fails('shellxquote', 'shellxquote=Something()', 'E520:')
+  call s:modeline_fails('spellfile', 'spellfile=Something()', 'E520:')
+  call s:modeline_fails('spellsuggest', 'spellsuggest=Something()', 'E520:')
+  call s:modeline_fails('tcldll', 'tcldll=Something()', 'E520:')
+  call s:modeline_fails('titleold', 'titleold=Something()', 'E520:')
+  call s:modeline_fails('viewdir', 'viewdir=Something()', 'E520:')
+  call s:modeline_fails('viminfo', 'viminfo=Something()', 'E520:')
+  call s:modeline_fails('viminfofile', 'viminfofile=Something()', 'E520:')
+  call s:modeline_fails('winptydll', 'winptydll=Something()', 'E520:')
+  call s:modeline_fails('undodir', 'undodir=Something()', 'E520:')
+  " only check a few terminal options
+  call s:modeline_fails('t_AB', 't_AB=Something()', 'E520:')
+  call s:modeline_fails('t_ce', 't_ce=Something()', 'E520:')
+  call s:modeline_fails('t_sr', 't_sr=Something()', 'E520:')
+  call s:modeline_fails('t_8b', 't_8b=Something()', 'E520:')
+endfunc
+
+func Test_modeline_fails_modelineexpr()
+  call s:modeline_fails('balloonexpr', 'balloonexpr=Something()', 'E992:')
+  call s:modeline_fails('foldexpr', 'foldexpr=Something()', 'E992:')
+  call s:modeline_fails('foldtext', 'foldtext=Something()', 'E992:')
+  call s:modeline_fails('formatexpr', 'formatexpr=Something()', 'E992:')
+  call s:modeline_fails('guitablabel', 'guitablabel=Something()', 'E992:')
+  call s:modeline_fails('iconstring', 'iconstring=Something()', 'E992:')
+  call s:modeline_fails('includeexpr', 'includeexpr=Something()', 'E992:')
+  call s:modeline_fails('indentexpr', 'indentexpr=Something()', 'E992:')
+  call s:modeline_fails('rulerformat', 'rulerformat=Something()', 'E992:')
+  call s:modeline_fails('statusline', 'statusline=Something()', 'E992:')
+  call s:modeline_fails('tabline', 'tabline=Something()', 'E992:')
+  call s:modeline_fails('titlestring', 'titlestring=Something()', 'E992:')
 endfunc
diff --git a/src/version.c b/src/version.c
index b2fcbfb..bcc9aef 100644
--- a/src/version.c
+++ b/src/version.c
@@ -768,6 +768,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1366,
+/**/
     1365,
 /**/
     1364,