diff --git a/README.md b/README.md
index 2397fc6..a8b5c7b 100644
--- a/README.md
+++ b/README.md
@@ -19,7 +19,6 @@ This module shares helpers among all [SPHERE.IO](http://sphere.io/) Node.js comp
     * [Underscore](#underscore)
       * [_.deepClone](#_deepclone)
       * [_.prettify](#_prettify)
-      * [_.prettifyError](#_prettifyerror)
       * [_.percentage](#_percentage)
       * [_.stringifyQuery](#_stringifyquery)
       * [_.parseQuery](#_parsequery)
@@ -208,7 +207,7 @@ cloned = _.deepClone(obj)
 ```
 
 ##### `_.prettify`
-Returns a prettify JSON object
+Returns a pretty-print formatted JSON string.
 
 ```coffeescript
 obj = foo: 'bar'
@@ -218,9 +217,8 @@ pretty = _.prettify(obj)
 #   "foo": "bar"
 # }"
 ```
-
-##### `_.prettifyError`
-Returns either a prettify JSON object or the Error stack
+In case the object is an instance of `Error`, the error stack is returned
+untouched.
 
 ```coffeescript
 e = new Error 'foo'
@@ -231,13 +229,6 @@ prettyOrStack = _.prettifyError(e)
 #   at Object.InjectedScript._evaluateOn (<anonymous>:613:39)
 #   at Object.InjectedScript._evaluateAndWrap (<anonymous>:573:52)
 #   at Object.InjectedScript.evaluate (<anonymous>:492:21)"
-
-obj = foo: 'bar'
-pretty = _.prettifyError(obj)
-# => pretty JSON
-# "{
-#   "foo": "bar"
-# }"
 ```
 
 ##### `_.percentage`
diff --git a/src/coffee/mixins/underscore.coffee b/src/coffee/mixins/underscore.coffee
index 125f190..2f1b2e5 100644
--- a/src/coffee/mixins/underscore.coffee
+++ b/src/coffee/mixins/underscore.coffee
@@ -22,25 +22,17 @@ module.exports =
     JSON.parse(JSON.stringify(obj))
 
   ###*
-   * Stringifies a JSON object in a pretty format
+   * Stringifies a JSON object in a pretty format. In case of an error object,
+   *   the error stack is returned untouched.
    * @param {Object} obj A JSON object
    * @param {Number} [indentation] The indentation number (default 2)
    * @return {String} A pretty string
   ###
   prettify: (obj, indentation = 2) ->
-    JSON.stringify obj, null, indentation
-
-  ###*
-   * Returns either a pretty string (from JSON object) or the error stack
-   * @param {Object} objOrError Either a JSON object or an Error
-   * @param {Number} [indentation] The indentation number (default 2)
-   * @return {String} A pretty string or the error stack
-  ###
-  prettifyError: (objOrError, indentation = 2) ->
-    if objOrError instanceof Error
-      objOrError.stack
+    if obj instanceof Error
+      obj.stack
     else
-      @prettify objOrError, indentation
+      JSON.stringify obj, null, indentation
 
   ###*
    * Returns the percentage of the given values
diff --git a/src/spec/mixins/underscore.spec.coffee b/src/spec/mixins/underscore.spec.coffee
index be7c1ac..976c0ff 100644
--- a/src/spec/mixins/underscore.spec.coffee
+++ b/src/spec/mixins/underscore.spec.coffee
@@ -16,7 +16,6 @@ describe 'Mixins', ->
       _.mixin _u
       expect(_.deepClone).toBeDefined()
       expect(_.prettify).toBeDefined()
-      expect(_.prettifyError).toBeDefined()
       expect(_.percentage).toBeDefined()
       expect(_.stringifyQuery).toBeDefined()
       expect(_.parseQuery).toBeDefined()
@@ -66,14 +65,9 @@ describe 'Mixins', ->
     it 'should prettify JSON with custom indentation', ->
       expect(_u.prettify {foo: 'bar'}, 4).toBe '{\n    "foo": "bar"\n}'
 
-  describe '_u :: prettifyError', ->
-
     it 'should return stack trace', ->
       e = new Error 'foo'
-      expect(_u.prettifyError e).toEqual e.stack
-
-    it 'should return pretty JSON', ->
-      expect(_u.prettifyError {foo: 'bar'}).toBe '{\n  "foo": "bar"\n}'
+      expect(_u.prettify e).toEqual e.stack
 
   describe '_u :: percentage', ->