diff --git a/Lib/fontParts/base/font.py b/Lib/fontParts/base/font.py
index aba66ef8..ea36b63c 100644
--- a/Lib/fontParts/base/font.py
+++ b/Lib/fontParts/base/font.py
@@ -1,4 +1,5 @@
 import os
+from fontTools import ufoLib
 from fontParts.base.errors import FontPartsError
 from fontParts.base.base import dynamicProperty, InterpolationMixin
 from fontParts.base.layer import _BaseGlyphVendor
@@ -1454,7 +1455,10 @@ def _interpolate(self, factor, minFont, maxFont,
             dstLayer.interpolate(factor, minLayer, maxLayer,
                                  round=round, suppressError=suppressError)
         if self.layerOrder:
-            self.defaultLayer = self.getLayer(self.layerOrder[0])
+            if ufoLib.DEFAULT_LAYER_NAME in self.layerOrder:
+                self.defaultLayer = self.getLayer(ufoLib.DEFAULT_LAYER_NAME)
+            else:
+                self.defaultLayer = self.getLayer(self.layerOrder[0])
         # kerning and groups
         self.kerning.interpolate(factor, minFont.kerning, maxFont.kerning,
                                  round=round, suppressError=suppressError)
diff --git a/documentation/source/development/documenting.rst b/documentation/source/development/documenting.rst
index a0793f46..9028de99 100644
--- a/documentation/source/development/documenting.rst
+++ b/documentation/source/development/documenting.rst
@@ -50,7 +50,7 @@ Do this: ::
 Don't do this: ::
 
   import random
-  from fontTools.world import *
+  from fontParts.world import *
 
   font = CurrentFont()
   print(font.glyphOrder)
@@ -225,7 +225,7 @@ fontParts
 * ``:ref:`type-identifier```
 * ``:ref:`type-color```
 * ``:ref:`type-transformation```
-* ``:ref:`type-immutable-list``` 
+* ``:ref:`type-immutable-list```
 
 general
 ^^^^^^^