diff --git a/cfg/posix.cfg b/cfg/posix.cfg
index 450647e65..f0cb79266 100644
--- a/cfg/posix.cfg
+++ b/cfg/posix.cfg
@@ -643,7 +643,7 @@
       <not-uninit/>
     </arg>
     <arg nr="2" direction="in">
-      <not-null/>
+      <valid>0:</valid>
       <not-uninit/>
       <not-bool/>
     </arg>
@@ -1323,6 +1323,7 @@ The function 'mktemp' is considered to be dangerous due to race conditions and s
     <returnValue type="int"/>
     <arg nr="1" direction="in">
       <not-uninit/>
+      <valid>0:</valid>
       <not-bool/>
     </arg>
     <arg nr="2" direction="in">
@@ -1332,6 +1333,7 @@ The function 'mktemp' is considered to be dangerous due to race conditions and s
     </arg>
     <arg nr="3" direction="in">
       <not-uninit/>
+      <valid>0:</valid>
     </arg>
     <arg nr="4" direction="in">
       <not-null/>
@@ -1346,6 +1348,7 @@ The function 'mktemp' is considered to be dangerous due to race conditions and s
     <returnValue type="int"/>
     <arg nr="1" direction="in">
       <not-uninit/>
+      <valid>0:</valid>
       <not-bool/>
     </arg>
     <arg nr="2" direction="in">