diff --git a/cfg/std.cfg b/cfg/std.cfg
index f7e4a662348..dac3d19be99 100644
--- a/cfg/std.cfg
+++ b/cfg/std.cfg
@@ -3313,7 +3313,6 @@ The obsolete function 'gets' is called. With 'gets' you'll get a buffer overrun
   </function>
   <!-- int fpclassify(double x); -->
   <function name="fpclassify,std::fpclassify">
-    <pure/>
     <use-retval/>
     <pure/>
     <returnValue type="int"/>
@@ -3329,7 +3328,6 @@ The obsolete function 'gets' is called. With 'gets' you'll get a buffer overrun
   <!-- bool isfinite(long double x); // since C++11 -->
   <!-- bool isfinite(Integral x); // since C++11 -->
   <function name="isfinite,std::isfinite">
-    <pure/>
     <use-retval/>
     <pure/>
     <returnValue type="int"/>