diff --git a/lib/debug.js b/lib/debug.js
index 6d7c333..b1457d6 100644
--- a/lib/debug.js
+++ b/lib/debug.js
@@ -69,6 +69,25 @@ function color() {
   return colors[prevColor++ % colors.length];
 }
 
+/**
+ * Humanize the given `ms`.
+ *
+ * @param {Number} m
+ * @return {String}
+ * @api private
+ */
+
+function humanize(ms) {
+  var sec = 1000
+    , min = 60 * 1000
+    , hour = 60 * min;
+
+  if (ms >= hour) return (ms / hour).toFixed(1) + 'h';
+  if (ms >= min) return (ms / min).toFixed(1) + 'm';
+  if (ms >= sec) return (ms / sec | 0) + 's';
+  return ms + 'ms';
+}
+
 /**
  * Create a debugger with the given `name`.
  *
@@ -93,7 +112,7 @@ function debug(name) {
     fmt = '  \033[9' + c + 'm' + name + ' '
       + '\033[3' + c + 'm\033[90m'
       + fmt + '\033[3' + c + 'm'
-      + ' +' + ms + 'ms\033[0m';
+      + ' +' + humanize(ms) + '\033[0m';
 
     console.error.apply(this, arguments);
   }