diff --git a/cfg/posix.cfg b/cfg/posix.cfg
index f765af998..4f2565c01 100644
--- a/cfg/posix.cfg
+++ b/cfg/posix.cfg
@@ -150,6 +150,28 @@
       <not-uninit/>
     </arg>
   </function>
+  <!-- int dup(int fildes);
+     see http://pubs.opengroup.org/onlinepubs/9699919799/functions/dup.html -->
+  <function name="dup">
+    <noreturn>false</noreturn>
+    <returnValue type="int"/>
+    <arg nr="1">
+      <not-bool/>
+      <not-uninit/>
+    </arg>
+  </function>
+  <!-- int dup(int fildes);
+     see http://pubs.opengroup.org/onlinepubs/9699919799/functions/dup.html -->
+  <function name="dup2">
+    <noreturn>false</noreturn>
+    <returnValue type="int"/>
+    <arg nr="1">
+  </arg>
+    <arg nr="2">
+      <not-bool/>
+      <not-uninit/>
+    </arg>
+  </function>
   <!-- int gettimeofday(struct timeval *tv, struct timezone *tz); -->
   <function name="gettimeofday">
     <noreturn>false</noreturn>
@@ -1643,6 +1665,28 @@ The function 'mktemp' is considered to be dangerous due to race conditions and s
       <not-bool/>
     </arg>
   </function>
+  <!-- int select(int nfds, fd_set *restrict readfds, fd_set * writefds, fd_set * errorfds, struct timeval *timeout);
+       see http://pubs.opengroup.org/onlinepubs/9699919799/functions/pselect.html -->
+  <function name="select">
+    <noreturn>false</noreturn>
+    <returnValue type="int"/>
+    <leak-ignore/>
+    <arg nr="1">
+      <!-- ignored -->
+    </arg>
+    <arg nr="2">
+      <!-- optional -->
+    </arg>
+    <arg nr="3">
+      <!-- optional -->
+    </arg>
+    <arg nr="4">
+      <!-- optional -->
+    </arg>
+    <arg nr="5">
+      <not-uninit/>
+    </arg>
+  </function>
   <!-- pid_t setpgrp(void); -->
   <function name="setpgrp">
     <returnValue type="pid_t"/>