diff --git a/cfg/avr.cfg b/cfg/avr.cfg
index 200607f0a..dba601157 100644
--- a/cfg/avr.cfg
+++ b/cfg/avr.cfg
@@ -220,4 +220,57 @@
   <!-- stdlib.h -->
   <define name="__ptr_t" value="void *"/>
   <define name="RAND_MAX" value="0x7FFF"/>
+  <function name="ltoa">
+	  <noreturn>false</noreturn>
+	  <leak-ignore/>
+	  <arg nr="1"><not-uninit/></arg>
+	  <arg nr="2"><not-null/><not-uninit/></arg>
+	  <arg nr="3"><not-null/><not-uninit/></arg>
+  </function>
+  <function name="utoa">
+	  <noreturn>false</noreturn>
+	  <leak-ignore/>
+	  <arg nr="1"><not-uninit/></arg>
+	  <arg nr="2"><not-null/><not-uninit/></arg>
+	  <arg nr="3"><not-null/><not-uninit/></arg>
+  </function>
+  <function name="ultoa">
+	  <noreturn>false</noreturn>
+	  <leak-ignore/>
+	  <arg nr="1"><not-uninit/></arg>
+	  <arg nr="2"><not-null/><not-uninit/></arg>
+	  <arg nr="3"><not-null/><not-uninit/></arg>
+  </function>
+   <function name="random">
+	  <noreturn>false</noreturn>
+	  <leak-ignore/>
+  </function>
+   <function name="random_r">
+	  <noreturn>false</noreturn>
+	  <leak-ignore/>
+	  <arg nr="1"><not-null/></arg>
+  </function>
+  <function name="srandom">
+	  <noreturn>false</noreturn>
+	  <leak-ignore/>
+	  <arg nr="1"><not-uninit/></arg>
+  </function>
+  <function name="dtostre">
+	  <noreturn>false</noreturn>
+	  <leak-ignore/>
+	  <arg nr="1"><not-uninit/></arg>
+	  <arg nr="2"><not-null/></arg>
+  </function>
+  <function name="dtostrf">
+	  <noreturn>false</noreturn>
+	  <leak-ignore/>
+	  <arg nr="1"><not-uninit/></arg>
+	  <arg nr="2"><not-uninit/></arg>
+	  <arg nr="3"><not-uninit/></arg>
+	  <arg nr="4"><not-null/></arg>
+  </function>  
+  <define name="RANDOM_MAX" value="0x7FFFFFFF"/>
+  <define name="DTOSTR_ALWAYS_SIGN" value="0x01"/>
+  <define name="DTOSTR_PLUS_SIGN" value="0x02"/>
+  <define name="DTOSTR_UPPERCASE" value="0x04"/>   
 </def>
diff --git a/cfg/posix.cfg b/cfg/posix.cfg
index 80e28b568..68c8ad539 100644
--- a/cfg/posix.cfg
+++ b/cfg/posix.cfg
@@ -53,7 +53,11 @@
   <function name="popen"><noreturn>false</noreturn><arg nr="1"><not-null/><not-uninit/></arg><arg nr="2"><not-null/><not-uninit/></arg></function>
   <function name="pclose"><noreturn>false</noreturn><arg nr="1"><not-null/><not-uninit/></arg></function>
   <function name="fdopen"><noreturn>false</noreturn><arg nr="1"><not-null/><not-uninit/></arg></function>
-
+  <function name="rand_r">
+       <noreturn>false</noreturn>
+       <leak-ignore/>
+       <arg nr="1"><not-null/></arg>
+  </function>
   <memory>
     <dealloc>free</dealloc>
     <alloc init="true">strdup</alloc>
diff --git a/cfg/std.cfg b/cfg/std.cfg
index ffffe0785..081c650fa 100644
--- a/cfg/std.cfg
+++ b/cfg/std.cfg
@@ -262,6 +262,14 @@
        <arg nr="1"><not-null/><not-uninit/></arg>
        <arg nr="2"><not-null/><not-uninit/></arg>
   </function>
+  <function name="rand">
+       <noreturn>false</noreturn>
+       <leak-ignore/>
+  </function>
+  <function name="srand">
+       <noreturn>false</noreturn>
+       <leak-ignore/>
+  </function>
   <function name="ldiv">
        <noreturn>false</noreturn>
        <leak-ignore/>