diff --git a/runtime/doc/starting.txt b/runtime/doc/starting.txt
index f7e98c7..1e7daa6 100644
--- a/runtime/doc/starting.txt
+++ b/runtime/doc/starting.txt
@@ -1,4 +1,4 @@
-*starting.txt*  For Vim version 9.0.  Last change: 2023 Oct 17
+*starting.txt*  For Vim version 9.0.  Last change: 2023 Oct 20
 
 
 		  VIM REFERENCE MANUAL    by Bram Moolenaar
@@ -249,10 +249,10 @@
 					*-Z* *restricted-mode* *E145* *E981*
 -Z		Restricted mode.  All commands that make use of an external
 		shell are disabled.  This includes suspending with CTRL-Z,
-		":sh", filtering, the system() function, backtick expansion
+		":sh", filtering, the |system()| function, backtick expansion
 		and libcall().
-		Also disallowed are delete(), rename(), mkdir(), job_start(),
-		etc.
+		Also disallowed are |delete()|, |rename()|, |mkdir()|,
+		|job_start()|, |setenv()| etc.
 		Interfaces, such as Python, Ruby and Lua, are also disabled,
 		since they could be used to execute shell commands.  Perl uses
 		the Safe module.
diff --git a/src/evalfunc.c b/src/evalfunc.c
index f9b81c6..9e4e26b 100644
--- a/src/evalfunc.c
+++ b/src/evalfunc.c
@@ -9723,6 +9723,12 @@
     if (in_vim9script() && check_for_string_arg(argvars, 0) == FAIL)
 	return;
 
+    // seting an environment variable may be dangerous, e.g. you could
+    // setenv GCONV_PATH=/tmp and then have iconv() unexpectedly call
+    // a shell command using some shared library:
+    if (check_restricted() || check_secure())
+	return;
+
     name = tv_get_string_buf(&argvars[0], namebuf);
     if (argvars[1].v_type == VAR_SPECIAL
 				      && argvars[1].vval.v_number == VVAL_NULL)
diff --git a/src/version.c b/src/version.c
index 890e92c..2bcdfc9 100644
--- a/src/version.c
+++ b/src/version.c
@@ -705,6 +705,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2070,
+/**/
     2069,
 /**/
     2068,