diff --git a/pkgtool.pm b/pkgtool.pm
index c47a429..87f4a8b 100644
--- a/pkgtool.pm
+++ b/pkgtool.pm
@@ -3261,6 +3261,7 @@ sub get_install_sets ($)
 		return 1;
 	}
 	my $flags = {};
+	my $globalflags = {};
 	my $pkgsets = $$config{'package-sets'};
 	$pkgsets = {} unless defined $pkgsets;
 	foreach my $line (split /\n/, $response->decoded_content) {
@@ -3291,6 +3292,21 @@ sub get_install_sets ($)
 				$$flags{$value} = 1;
 			}
 		}
+		if ($key eq 'flag') {
+			my $flag;
+			if ($value =~ /^([^=]+)=(.*)$/o) {
+				$flag = $1;
+				$value = $2;
+			}
+			else {
+				$flag = $value;
+				$value = 1;
+			}
+			if (! defined $$globalflags{$flag}) {
+				print_log('global', DEBUG1, 'Adding global flag %s=%s', $flag, $value);
+				$$globalflags{$flag} = $value;
+			}
+		}
 	}
 	my $genvars = $$config{'generic-variables'};
 	foreach my $pkgflag (keys %$flags) {
@@ -3299,6 +3315,13 @@ sub get_install_sets ($)
 			expression => 1
 		};
 	}
+	foreach my $flag (keys %$globalflags) {
+		my $value = $$globalflags{$flag};
+		push @$genvars, {
+			variable => $flag,
+			expression => $value
+		};
+	}
 	return undef;
 }