diff --git a/cfg/posix.cfg b/cfg/posix.cfg
index d14413c98..9bb7b1b84 100644
--- a/cfg/posix.cfg
+++ b/cfg/posix.cfg
@@ -2306,16 +2306,19 @@ The function 'mktemp' is considered to be dangerous due to race conditions and s
       <valid>0:</valid>
     </arg>
     <arg nr="2" direction="in">
+      <not-uninit/>
       <minsize type="argvalue" arg="3"/>
     </arg>
     <arg nr="3" direction="in">
       <not-uninit/>
+      <valid>0:</valid>
     </arg>
     <arg nr="4" direction="in">
       <not-uninit/>
       <not-bool/>
     </arg>
   </function>
+  <!-- https://man7.org/linux/man-pages/man3/sendto.3p.html -->
   <!-- ssize_t sendto(int sockfd, const void *buf, size_t len, int flags,
                       const struct sockaddr *dest_addr, socklen_t addrlen); -->
   <function name="sendto">
diff --git a/test/cfg/posix.c b/test/cfg/posix.c
index 53699eb52..b6f5fd548 100644
--- a/test/cfg/posix.c
+++ b/test/cfg/posix.c
@@ -601,6 +601,13 @@ void validCode(va_list valist_arg1, va_list valist_arg2)
     }
 }
 
+ssize_t nullPointer_send(int socket, const void *buf, size_t len, int flags)
+{
+    // cppcheck-suppress nullPointer
+    (void) send(socket, NULL, len, flags);
+    return send(socket, buf, len, flags);
+}
+
 ssize_t nullPointer_sendto(int socket, const void *message, size_t length,
                            int flags, const struct sockaddr *dest_addr,
                            socklen_t dest_len)