diff --git a/doc/Makefile.in b/doc/Makefile.in
index b79beb5..1915f2a 100644
--- a/doc/Makefile.in
+++ b/doc/Makefile.in
@@ -199,6 +199,10 @@ objcheck: all
 		fi;						\
 	done
 
+# check for stale references
+refcheck:
+	@./refcheck.pl $(OBJECTS)
+
 install:
 	mkdir -p $(DESTDIR)/$(MANDIR)/man3 || exit
 	cp *$(GZIP_SUFFIX) $(DESTDIR)/$(MANDIR)/man3 || exit
diff --git a/doc/refcheck.pl b/doc/refcheck.pl
new file mode 100755
index 0000000..1ed3a65
--- /dev/null
+++ b/doc/refcheck.pl
@@ -0,0 +1,27 @@
+#!/usr/bin/perl
+
+use warnings;
+use strict;
+
+my @files = @ARGV;
+
+my $h;
+
+foreach my $file (@files) {
+    $h->{$file} = 1;
+}
+
+foreach my $file (@files) {
+    open(my $fh, "<", $file) or die "cannot open < $file: $!";
+    while (<$fh>) {
+        chomp;
+        if ($_ =~ /\.Xr ((ck|CK)_[a-zA-Z_]+) ([0-9])/) {
+	    my $name = $1;
+	    my $section = $3;
+	    if (!$h->{$name}) {
+		print STDERR "$file: ref to missing ${name}($section)\n";
+	    }
+        }
+    }
+    close($fh) or die("cannot close $file: $!");
+}