diff --git a/lib/dirsum.js b/lib/dirsum.js
index 33e98dd..0d97930 100644
--- a/lib/dirsum.js
+++ b/lib/dirsum.js
@@ -61,7 +61,7 @@ function digest(root, method, callback) {
 
         if (stats.isDirectory()) {
           return digest(path, method, function(err, hash) {
-            if (err) return hash;
+            if (err) return callback(err);
 
             hashes[f] = hash;
             if (++hashed >= files.length) {