--- lib/ModPerl/BuildMM.pm      (revision 648960)
+++ lib/ModPerl/BuildMM.pm      (working copy)
@@ -359,7 +359,7 @@

     $apr_config ||= $build->get_apr_config();

-    if ($path =~ m/(Thread|Global)Mutex/) {
+    if ($path =~ m/(Thread|Global)(Mutex|RWLock)/) {
         return unless $apr_config->{HAS_THREADS};
     }