AC_CACHE_CHECK([what is the type of the fifth argument of getsockopt],
                        wx_cv_type_getsockopt5,
             [
+                dnl Note that the rules for compatibility of pointers
+                dnl are somewhat different between C and C++, so code 
+                dnl that fails in C++ may not even give a warning about
+                dnl converting between incompatible pointer types in C.
+                dnl So this test needs to be done in C++ mode.
+                AC_LANG_PUSH(C++)
                 AC_TRY_COMPILE(
                     [
                         #include <sys/types.h>
                     ],
                     wx_cv_type_getsockopt5=socklen_t,
                     [
-                        dnl Note that the rules for compatibility of pointers
-                        dnl are somewhat different between C and C++, so code 
-                        dnl that fails in C++ may not even give a warning about
-                        dnl converting between incompatible pointer types in C.
-                        dnl So this test needs to be done in C++ mode.
-                        AC_LANG_PUSH(C++)
                         AC_TRY_COMPILE(
                             [
                                 #include <sys/types.h>
                                 wx_cv_type_getsockopt5=unknown
                             )
                         )
-                        AC_LANG_POP()
                     ]
                 )
+                AC_LANG_POP()
             ])
 
         if test "$wx_cv_type_getsockopt5" = "unknown"; then