diff --git a/cfg/std.cfg b/cfg/std.cfg
index 27909cb12..d2856c128 100644
--- a/cfg/std.cfg
+++ b/cfg/std.cfg
@@ -1162,6 +1162,25 @@
       <not-uninit/>
     </arg>
   </function>
+  <!-- errno_t ctime_s(char *buffer, rsize_t bufsz, const time_t *time); // since C11 -->
+  <function name="ctime_s">
+    <noreturn>false</noreturn>
+    <returnValue type="errno_t"/>
+    <leak-ignore/>
+    <arg nr="1" direction="out">
+      <not-null/>
+      <minsize type="argvalue" arg="2"/>
+    </arg>
+    <arg nr="2" direction="in">
+      <not-uninit/>
+      <valid>26:</valid>
+    </arg>
+    <arg nr="3" direction="in">
+      <not-null/>
+      <not-uninit/>
+      <not-bool/>
+    </arg>
+  </function>
   <!-- double difftime(time_t time2, time_t time1); -->
   <function name="difftime,std::difftime">
     <use-retval/>