diff --git a/tools/mkdep.pl b/tools/mkdep.pl
index 50d509c3..8de0522e 100755
--- a/tools/mkdep.pl
+++ b/tools/mkdep.pl
@@ -52,9 +52,9 @@ $barrier = "#-- Everything below is generated by mkdep.pl - do not edit --#\n";
 #
 sub scandeps($) {
     my($file) = @_;
-    my($line, $nf);
-    my(@xdeps) = ();
-    my(@mdeps) = ();
+    my $line;
+    my @xdeps = ();
+    my @mdeps = ();
 
     open(my $fh, '<', $file)
 	or return;		# If not openable, assume generated
@@ -64,7 +64,11 @@ sub scandeps($) {
 	$line =~ s:/\*.*\*/::g;
 	$line =~ s://.*$::;
 	if ( $line =~ /^\s*\#\s*include\s+\"(.*)\"\s*$/ ) {
-	    $nf = $1;
+	    my $nf = $1;
+	    if (!defined($dep_path{$nf})) {
+		die "$0: cannot determine path for dependency: $file -> $nf\n";
+	    }
+	    $nf = $dep_path{$nf};
 	    push(@mdeps, $nf);
 	    push(@xdeps, $nf) unless ( defined($deps{$nf}) );
 	}
@@ -72,21 +76,20 @@ sub scandeps($) {
     close($fh);
     $deps{$file} = [@mdeps];
 
-    foreach $file ( @xdeps ) {
-	scandeps($file);
+    foreach my $xf ( @xdeps ) {
+	scandeps($xf);
     }
 }
 
 # %deps contains direct dependencies.  This subroutine resolves
 # indirect dependencies that result.
-sub alldeps($) {
-    my($file) = @_;
-    my(%adeps);
-    my($dep,$idep);
+sub alldeps($$) {
+    my($file, $level) = @_;
+    my %adeps;
 
-    foreach $dep ( @{$deps{$file}} ) {
+    foreach my $dep ( @{$deps{$file}} ) {
 	$adeps{$dep} = 1;
-	foreach $idep ( alldeps($dep) ) {
+	foreach my $idep ( alldeps($dep, $level+1) ) {
 	    $adeps{$idep} = 1;
 	}
     }
@@ -97,7 +100,7 @@ sub alldeps($) {
 # This almost certainly works only on relative filenames...
 sub convert_file($$) {
     my($file,$sep) = @_;
-    my(@fspec) = (basename($file));
+    my @fspec = (basename($file));
     while ( ($file = dirname($file)) ne File::Spec->curdir() &&
 	    $file ne File::Spec->rootdir() ) {
 	unshift(@fspec, basename($file));
@@ -119,7 +122,7 @@ sub convert_file($$) {
 sub insert_deps($) {
     my($file) = @_;
     $nexttemp++;		# Unique serial number for each temp file
-    my($tmp) = File::Spec->catfile(dirname($file), 'tmp.'.$nexttemp);
+    my $tmp = File::Spec->catfile(dirname($file), 'tmp.'.$nexttemp);
 
     open(my $in, '<', $file)
 	or die "$0: Cannot open input: $file\n";
@@ -180,17 +183,9 @@ sub insert_deps($) {
 	    $str = convert_file($ofile, $sep).$obj.':';
 	    $len = length($str);
 	    print $out $str;
-	    foreach $dep ($dfile, alldeps($dfile)) {
+	    foreach $dep ($dfile, alldeps($dfile,1)) {
 		unless ($do_exclude{$dep}) {
-		    if (!defined($dep_path{$dep})) {
-			if ($dep eq $dfile) {
-			    $dep_path{$dep} = $dfile;
-			    print STDERR "Self: $dep -> $dfile\n";
-			} else {
-			    die "$0: unknown dependency: $dep\n";
-			}
-		    }
-		    $str = convert_file($dep_path{$dep}, $sep);
+		    $str = convert_file($dep, $sep);
 		    $sl = length($str)+1;
 		    if ( $len+$sl > $maxline-2 ) {
 			print $out ' ', $cont, "\n ", $str;
@@ -238,6 +233,8 @@ while ( defined(my $arg = shift(@ARGV)) ) {
     }
 }
 
+my @cfiles = ();
+
 foreach my $dir ( @files ) {
     opendir(DIR, $dir) or die "$0: Cannot open directory: $dir";
 
@@ -245,7 +242,7 @@ foreach my $dir ( @files ) {
 	$path = ($dir eq File::Spec->curdir())
 	    ? $file : File::Spec->catfile($dir,$file);
 	if ( $file =~ /\.[Cc]$/ ) {
-	    scandeps($path);
+	    push(@cfiles, $path);
 	} elsif ( $file =~ /\.[Hh]$/ ) {
 	    print STDERR "Filesystem: $file -> $path\n";
 	    $dep_path{$file} = $path;
@@ -254,6 +251,10 @@ foreach my $dir ( @files ) {
     closedir(DIR);
 }
 
-foreach $mkfile ( @mkfiles ) {
+foreach my $cfile ( @cfiles ) {
+    scandeps($cfile);
+}
+
+foreach my $mkfile ( @mkfiles ) {
     insert_deps($mkfile);
 }