diff --git a/cfg/posix.cfg b/cfg/posix.cfg
index bcd726a88..170ae5d16 100644
--- a/cfg/posix.cfg
+++ b/cfg/posix.cfg
@@ -3598,6 +3598,26 @@ The function 'mktemp' is considered to be dangerous due to race conditions and s
       <not-uninit/>
     </arg>
   </function>
+  <function name="swab">
+	<returnValue type="void"/>
+	<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="sync">
+	<returnValue type="void"/>
+	<noreturn>false</noreturn>
+  </function>
   <memory>
     <alloc init="true">strdup</alloc>
     <alloc init="true">strndup</alloc>