diff --git a/reactos/tools/rbuild/XML.cpp b/reactos/tools/rbuild/XML.cpp
index a9723c3a9e4..96547562496 100644
--- a/reactos/tools/rbuild/XML.cpp
+++ b/reactos/tools/rbuild/XML.cpp
@@ -172,21 +172,27 @@ Path::RelativeFromWorkingDirectory ()
 string
 Path::RelativeFromWorkingDirectory ( const string& path )
 {
-	vector<string> vwork, vpath, vout;
-	Path::Split ( vwork, working_directory, true );
+	return Path::RelativeFromDirectory ( path, working_directory );
+}
+
+string
+Path::RelativeFromDirectory ( const string& path, const string& base_directory )
+{
+	vector<string> vbase, vpath, vout;
+	Path::Split ( vbase, base_directory, true );
 	Path::Split ( vpath, path, true );
 #ifdef WIN32
 	// this squirreliness is b/c win32 has drive letters and *nix doesn't...
 	// not possible to do relative across different drive letters
-	if ( vwork[0] != vpath[0] )
+	if ( vbase[0] != vpath[0] )
 		return path;
 #endif
 	size_t i = 0;
-	while ( i < vwork.size() && i < vpath.size() && vwork[i] == vpath[i] )
+	while ( i < vbase.size() && i < vpath.size() && vbase[i] == vpath[i] )
 		++i;
-	if ( i < vwork.size() )
+	if ( i < vbase.size() )
 	{
-		// path goes above our working directory, we will need some ..'s
+		// path goes above our base directory, we will need some ..'s
 		for ( size_t j = 0; j < i; j++ )
 			vout.push_back ( ".." );
 	}
diff --git a/reactos/tools/rbuild/XML.h b/reactos/tools/rbuild/XML.h
index d22ab987161..38ad86c3a09 100644
--- a/reactos/tools/rbuild/XML.h
+++ b/reactos/tools/rbuild/XML.h
@@ -44,6 +44,7 @@ public:
 
 	std::string RelativeFromWorkingDirectory ();
 	static std::string RelativeFromWorkingDirectory ( const std::string& path );
+	static std::string RelativeFromDirectory ( const std::string& path, const std::string& base_directory);
 
 	static void Split ( std::vector<std::string>& out,
 	                    const std::string& path,