diff --git a/lib/utils.js b/lib/utils.js
index <HASH>..<HASH> 100644
--- a/lib/utils.js
+++ b/lib/utils.js
@@ -35,22 +35,6 @@ utils.last = function(arr, n) {
 };
 
 /**
- * Compose a matcher function with the given patterns
- */
-
-utils.compose = function(patterns, options, matcher) {
-  var fns = patterns.map(function(pattern) {
-    return matcher(pattern, options);
-  });
-
-  return function(file) {
-    var len = fns.length;
-    while (len--) if (fns[len](file)) return true;
-    return false;
-  };
-};
-
-/**
  * Get the `Snapdragon` instance to use
  */
 
@@ -220,6 +204,7 @@ utils.stripDrive = function(fp) {
  */
 
 utils.stripPrefix = function(str) {
+  if (!str || typeof str !== 'string') return str;
   if (str.charAt(0) !== '.') {
     return str;
   }
move `compose` to main file