diff --git a/webtools/tinderbox/processbuild.pl b/webtools/tinderbox/processbuild.pl
index a582b81e05d6..be621fb3fb24 100755
--- a/webtools/tinderbox/processbuild.pl
+++ b/webtools/tinderbox/processbuild.pl
@@ -74,7 +74,7 @@ require "$tinderbox{tree}/treedata.pl" if -r "$tinderbox{tree}/treedata.pl";
 if (defined $warning_buildnames_pat
     and $tinderbox{build} =~ /^$warning_buildnames_pat$/
     and $tinderbox{status} eq 'success') {
-  system './warnings.pl';
+  system './warnings.pl $tinderbox{tree}';
 }
 
 # Bloat data
diff --git a/webtools/tinderbox/warnings.pl b/webtools/tinderbox/warnings.pl
index 8c829e413896..697a17a3df9c 100755
--- a/webtools/tinderbox/warnings.pl
+++ b/webtools/tinderbox/warnings.pl
@@ -74,15 +74,20 @@ use FileHandle;
 #  {...}, ...
 # )
 
+sub usage {
+  warn "usage: warnings.pl <tree_directory>\n";
+}
 
 # This is for gunzip (should add a configure script to handle this).
 $ENV{PATH} .= ":/usr/local/bin";
 
-$debug = 1 if $ARGV[0] eq '--debug';
+$debug = 1, shift @ARGV if $ARGV[0] eq '--debug';
+
+&usage, die "Error: Not enough arguments\n" if $#ARGV == -1;
 
 # Load tinderbox build data.
 #   (So we can find the last successful build for the tree of intestest.)
-$tree = 'SeaMonkey';
+$tree = shift @ARGV;
 # tinderbox/tbglobals.pl uses many shameful globals
 $form{tree} = $tree;
 require 'tbglobals.pl';