   #
   _displayOutput: (value) ->
     negative = false
-    if value < 0
-      negative = true
-      value *= -1
-    @_displayValue String(value), negative
+    unless @_isError value
+      if value < 0
+        negative = true
+        value *= -1
+      value = String(value)
+    @_displayValue value, negative
 
   # Displays the given value with optional negative flag.
   #

  # @private
  #
  _displayValue: (value, negative) ->
    value = '0' if value is ''
    value += '.' if value.indexOf('.') < 0
    value = value.replace /\./, @options.point
    @$element.find('.jscalc-display')

      .end()
      .find('.jscalc-sign')
        .toggleClass('active', negative)
      .end()
      .find('.jscalc-error')
        .toggleClass('active', error)
    return

  # Enters the given digit.
