diff --git a/src/indent.c b/src/indent.c
index 8dd4ef9..8e9b0d1 100644
--- a/src/indent.c
+++ b/src/indent.c
@@ -71,7 +71,7 @@
 	int n = atoi((char *)cp);
 
 	// Catch negative values, overflow and ridiculous big values.
-	if (n < 0 || n > 9999)
+	if (n < 0 || n > TABSTOP_MAX)
 	{
 	    semsg(_(e_invalid_argument_str), cp);
 	    vim_free(*array);
@@ -1649,7 +1649,7 @@
 	emsg(_(e_argument_must_be_positive));
 	return;
     }
-    if (new_ts < 0 || new_ts > 9999)
+    if (new_ts < 0 || new_ts > TABSTOP_MAX)
     {
 	semsg(_(e_invalid_argument_str), eap->arg);
 	return;
diff --git a/src/option.c b/src/option.c
index bb952fe..482e960 100644
--- a/src/option.c
+++ b/src/option.c
@@ -3752,6 +3752,11 @@
 	errmsg = e_argument_must_be_positive;
 	curbuf->b_p_ts = 8;
     }
+    else if (curbuf->b_p_ts > TABSTOP_MAX)
+    {
+	errmsg = e_invalid_argument;
+	curbuf->b_p_ts = 8;
+    }
     if (p_tm < 0)
     {
 	errmsg = e_argument_must_be_positive;
@@ -5983,7 +5988,7 @@
 	    if (p_vsts && p_vsts != empty_option)
 		(void)tabstop_set(p_vsts, &buf->b_p_vsts_array);
 	    else
-		buf->b_p_vsts_array = 0;
+		buf->b_p_vsts_array = NULL;
 	    buf->b_p_vsts_nopaste = p_vsts_nopaste
 				 ? vim_strsave(p_vsts_nopaste) : NULL;
 #endif
@@ -6803,9 +6808,7 @@
 	    if (buf->b_p_vsts)
 		free_string_option(buf->b_p_vsts);
 	    buf->b_p_vsts = empty_option;
-	    if (buf->b_p_vsts_array)
-		vim_free(buf->b_p_vsts_array);
-	    buf->b_p_vsts_array = 0;
+	    VIM_CLEAR(buf->b_p_vsts_array);
 #endif
 	}
 
@@ -6851,12 +6854,11 @@
 		free_string_option(buf->b_p_vsts);
 	    buf->b_p_vsts = buf->b_p_vsts_nopaste
 			 ? vim_strsave(buf->b_p_vsts_nopaste) : empty_option;
-	    if (buf->b_p_vsts_array)
-		vim_free(buf->b_p_vsts_array);
+	    vim_free(buf->b_p_vsts_array);
 	    if (buf->b_p_vsts && buf->b_p_vsts != empty_option)
 		(void)tabstop_set(buf->b_p_vsts, &buf->b_p_vsts_array);
 	    else
-		buf->b_p_vsts_array = 0;
+		buf->b_p_vsts_array = NULL;
 #endif
 	}
 
diff --git a/src/testdir/test_options.vim b/src/testdir/test_options.vim
index 2265894..2af13d9 100644
--- a/src/testdir/test_options.vim
+++ b/src/testdir/test_options.vim
@@ -368,6 +368,8 @@
   call assert_fails('set shiftwidth=-1', 'E487:')
   call assert_fails('set sidescroll=-1', 'E487:')
   call assert_fails('set tabstop=-1', 'E487:')
+  call assert_fails('set tabstop=10000', 'E474:')
+  call assert_fails('set tabstop=5500000000', 'E474:')
   call assert_fails('set textwidth=-1', 'E487:')
   call assert_fails('set timeoutlen=-1', 'E487:')
   call assert_fails('set updatecount=-1', 'E487:')
diff --git a/src/version.c b/src/version.c
index 0caa33a..8275e8f 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    4245,
+/**/
     4244,
 /**/
     4243,
diff --git a/src/vim.h b/src/vim.h
index 15ed626..86acb6d 100644
--- a/src/vim.h
+++ b/src/vim.h
@@ -2085,6 +2085,8 @@
 
 #define DICT_MAXNEST 100	// maximum nesting of lists and dicts
 
+#define TABSTOP_MAX 9999
+
 #ifdef FEAT_CLIPBOARD
 
 // VIM_ATOM_NAME is the older Vim-specific selection type for X11.  Still