diff --git a/cfg/posix.cfg b/cfg/posix.cfg
index 9da8742e7..034d9610a 100644
--- a/cfg/posix.cfg
+++ b/cfg/posix.cfg
@@ -1059,7 +1059,6 @@ The function 'mktemp' is considered to be dangerous due to race conditions and s
       <not-uninit/>
     </arg>
     <arg nr="2">
-      <not-null/>
       <minsize type="argvalue" arg="3"/>
     </arg>
     <arg nr="3">
@@ -1076,7 +1075,6 @@ The function 'mktemp' is considered to be dangerous due to race conditions and s
     </arg>
     <arg nr="2">
       <not-uninit/>
-      <not-null/>
       <minsize type="argvalue" arg="3"/>
     </arg>
     <arg nr="3">
diff --git a/test/cfg/posix.c b/test/cfg/posix.c
index 4c76d7b40..5c5c21e89 100644
--- a/test/cfg/posix.c
+++ b/test/cfg/posix.c
@@ -56,10 +56,12 @@ void nullPointer(char *p, int fd)
     // cppcheck-suppress nullPointer
     // cppcheck-suppress utimeCalled
     utime(NULL, NULL);
-    // cppcheck-suppress nullPointer
+    // not implemented yet: cppcheck-suppress nullPointer
     read(fd,NULL,42);
-    // cppcheck-suppress nullPointer
+    read(fd,NULL,0);
+    // not implemented yet: cppcheck-suppress nullPointer
     write(fd,NULL,42);
+    write(fd,NULL,0);
 }
 
 void memleak_getaddrinfo()