diff --git a/Build.PL b/Build.PL
index 38b471bb7..69d1af618 100644
--- a/Build.PL
+++ b/Build.PL
@@ -26,8 +26,6 @@ my %prereqs = qw(
 );
 my %recommends = qw(
     Class::XSAccessor               0
-    LWP::UserAgent                  0
-    Net::Bonjour                    0
     XML::SAX::ExpatXS               0
     Test::Harness                   0
 );
@@ -39,12 +37,19 @@ if ($gui) {
     %prereqs = qw(
     Class::Accessor                 0
     Wx                              0.9918
+    Socket                          2.016
     );
     %recommends = qw(
     Growl::GNTP                     0.15
     Wx::GLCanvas                    0
     OpenGL                          0
+    LWP::UserAgent                  0
+    Net::Bonjour                    0
     );
+    if ($^O eq 'MSWin32') {
+        # we need an up-to-date Win32::API because older aren't thread-safe (GH #2517)
+        $prereqs{'Win32::API'} = 0.79;
+    }
 } elsif ($xs_only) {
     %prereqs = %recommends = ();
 }
@@ -111,7 +116,7 @@ EOF
     foreach my $module (sort keys %modules) {
         my $version = $modules{$module};
         my @cmd = ($cpanm, @cpanm_args);
-        push @cmd, '-f', if $module eq 'OpenGL';  # temporary workaround for upstream bug in test
+        push @cmd, '--notest', if $module eq 'OpenGL';  # temporary workaround for upstream bug in test
         push @cmd, "$module~$version";
         if ($module eq 'XML::SAX::ExpatXS' && $^O eq 'MSWin32') {
             my $mingw = 'C:\dev\CitrusPerl\mingw64';