--- configure
+++ configure
@@ -2508,5 +2508,5 @@
     if test "$aix_use_runtimelinking" = yes; then
       # Warning - without using the other runtime loading flags (-brtl),
       # -berok will link without error, but may produce a broken library.
-      allow_undefined_flag_CXX='-berok'
+      allow_undefined_flag_CXX=unsupported
       # Determine the default libpath from the value encoded in an empty executable.