diff --git a/src/tools/msvc/build.pl b/src/tools/msvc/build.pl
index de50554e7e..b66f2c3b12 100644
--- a/src/tools/msvc/build.pl
+++ b/src/tools/msvc/build.pl
@@ -1,7 +1,9 @@
 # -*-perl-*- hey - emacs - this is a perl file
-
+#
+# Script that provides 'make' functionality for msvc builds.
+#
 # src/tools/msvc/build.pl
-
+#
 use strict;
 use warnings;
 
@@ -12,10 +14,22 @@ use Cwd;
 
 use Mkvcbuild;
 
+sub usage
+{
+	die("Usage: build.pl [ [ <configuration> ] <component> ]\n"
+	    . "Options are case-insensitive.\n"
+	    . "  configuration: Release | Debug.  This sets the configuration\n"
+	    . "    to build.  Default is Release.\n"
+	    . "  component: name of component to build.  An empty value means\n"
+	    . "    to build all components.\n");
+}
+
 chdir('../../..') if (-d '../msvc' && -d '../../../src');
 die 'Must run from root or msvc directory'
   unless (-d 'src/tools/msvc' && -d 'src');
 
+usage() unless scalar(@ARGV) <= 2;
+
 # buildenv.pl is for specifying the build environment settings
 # it should contain lines like:
 # $ENV{PATH} = "c:/path/to/bison/bin;$ENV{PATH}";
@@ -37,17 +51,20 @@ do "./src/tools/msvc/config.pl" if (-f "src/tools/msvc/config.pl");
 my $vcver = Mkvcbuild::mkvcbuild($config);
 
 # check what sort of build we are doing
-
 my $bconf     = $ENV{CONFIG}   || "Release";
 my $msbflags  = $ENV{MSBFLAGS} || "";
 my $buildwhat = $ARGV[1]       || "";
-if (uc($ARGV[0]) eq 'DEBUG')
+
+if (defined($ARGV[0]))
 {
-	$bconf = "Debug";
-}
-elsif (uc($ARGV[0]) ne "RELEASE")
-{
-	$buildwhat = $ARGV[0] || "";
+	if (uc($ARGV[0]) eq 'DEBUG')
+	{
+		$bconf = "Debug";
+	}
+	elsif (uc($ARGV[0]) ne "RELEASE")
+	{
+		$buildwhat = $ARGV[0] || "";
+	}
 }
 
 # ... and do it