diff --git a/cfg/std.cfg b/cfg/std.cfg
index 1e61407f34c..f7e4a662348 100644
--- a/cfg/std.cfg
+++ b/cfg/std.cfg
@@ -1074,7 +1074,6 @@
   </function>
   <!-- clock_t clock(void); -->
   <function name="clock">
-    <pure/>
     <use-retval/>
     <returnValue type="clock_t"/>
     <noreturn>false</noreturn>
@@ -1609,7 +1608,6 @@
   </function>
   <!-- int feof(FILE *stream); -->
   <function name="feof,std::feof">
-    <pure/>
     <use-retval/>
     <returnValue type="int"/>
     <noreturn>false</noreturn>
@@ -8605,7 +8603,7 @@ initializer list (7) string& replace (const_iterator i1, const_iterator i2, init
   <!-- bool std::map::contains( const Key& key ) const; // since C++20 -->
   <!-- template< class K > bool std::map::contains( const K& x ) const; // since C++20 -->
   <function name="std::map::contains">
-    <pure/>
+    <const/>
     <noreturn>false</noreturn>
     <returnValue type="bool"/>
     <use-retval/>