diff --git a/customblocks/wool.py b/customblocks/wool.py
new file mode 100644
index 000000000..67446bdf7
--- /dev/null
+++ b/customblocks/wool.py
@@ -0,0 +1,41 @@
+#from overviewer_core import textures
+
+@material(blockid=35, data=range(16), solid=True)
+def wool(self, blockid, data):
+    if data == 0: # white
+        texture = self.terrain_images[64]
+    elif data == 1: # orange
+        texture = self.terrain_images[210]
+    elif data == 2: # magenta
+        texture = self.terrain_images[194]
+    elif data == 3: # light blue
+        texture = self.terrain_images[178]
+    elif data == 4: # yellow
+        texture = self.terrain_images[162]
+    elif data == 5: # light green
+        texture = self.terrain_images[146]
+    elif data == 6: # pink
+        texture = self.terrain_images[130]
+    elif data == 7: # grey
+        texture = self.terrain_images[114]
+    elif data == 8: # light grey
+        texture = self.terrain_images[225]
+    elif data == 9: # cyan
+        texture = self.terrain_images[209]
+    elif data == 10: # purple
+        texture = self.terrain_images[193]
+    elif data == 11: # blue
+        texture = self.terrain_images[177]
+    elif data == 12: # brown
+        texture = self.terrain_images[161]
+    elif data == 13: # dark green
+        texture = self.terrain_images[145]
+        texture = Image.new("RGBA", (16, 16), 0x99FFFFFF)
+    elif data == 14: # red
+        texture = self.terrain_images[129]
+        texture = Image.open("/tmp/wool.png").convert("RGBA").resize((16,16))
+    elif data == 15: # black
+        texture = self.terrain_images[113]
+    
+    return self.build_block(texture, texture)
+
diff --git a/overviewer.py b/overviewer.py
index 612f1c932..66efa84c9 100755
--- a/overviewer.py
+++ b/overviewer.py
@@ -391,8 +391,10 @@ def main():
             worldcache[render['world']] = w
 
         # find or create the textures object
-        texopts = util.dict_subset(render, ["texturepath", "bgcolor", "northdirection"])
-        texopts_key = tuple(texopts.items())
+        texopts = util.dict_subset(render, ["texturepath", "bgcolor", "northdirection", "customblocks"])
+        texopts_red = util.dict_subset(texopts, ["texturepath", "bgcolor", "northdirection"])
+        texopts_red["customblocks"] = " ".join(texopts.get("customblocks", None))
+        texopts_key = tuple(texopts_red.items())
         if texopts_key not in texcache:
             tex = textures.Textures(**texopts)
             tex.generate()
diff --git a/overviewer_core/settingsDefinition.py b/overviewer_core/settingsDefinition.py
index a9c62c158..14993d3a3 100644
--- a/overviewer_core/settingsDefinition.py
+++ b/overviewer_core/settingsDefinition.py
@@ -86,6 +86,8 @@
             "poititle": Setting(required=False, validator=validateStr, default="Signs"),
             "customwebassets": Setting(required=False, validator=validateWebAssetsPath, default=None),
             "maxzoom": Setting(required=False, validator=validateInt, default=None),
+            "customblocks": Setting(required=False, validator=validateCustomblocks, default=None),
+
             # Remove this eventually (once people update their configs)
             "worldname": Setting(required=False, default=None,
                 validator=error("The option 'worldname' is now called 'world'. Please update your config files")),
diff --git a/overviewer_core/settingsValidators.py b/overviewer_core/settingsValidators.py
index 0c2a6ccbb..9ca1e512a 100644
--- a/overviewer_core/settingsValidators.py
+++ b/overviewer_core/settingsValidators.py
@@ -227,6 +227,18 @@ def validatePath(p):
     if not os.path.exists(abs_path):
         raise ValidationException("'%s' does not exist. Path initially given as '%s'" % (abs_path,p))
 
+def validateCustomblocks(p):
+    cb = []
+    for i in p:
+        ocb_path = os.path.join(util.get_program_path(), "customblocks", "%s.py" % i)
+        if os.path.isfile(ocb_path):
+            cb.append(ocb_path)
+        elif os.path.isfile(expand_path(i)):
+            cb.append(expand_path(i))
+        else:
+            raise ValidationException("Unable to find block definition file '%s'" % i)
+    return cb
+
 def make_dictValidator(keyvalidator, valuevalidator):
     """Compose and return a dict validator -- a validator that validates each
     key and value in a dictionary.
diff --git a/overviewer_core/textures.py b/overviewer_core/textures.py
index a49a8e441..7d2755f6c 100644
--- a/overviewer_core/textures.py
+++ b/overviewer_core/textures.py
@@ -37,11 +37,12 @@ class Textures(object):
     rendering. It accepts a background color, north direction, and
     local textures path.
     """
-    def __init__(self, texturepath=None, bgcolor=(26, 26, 26, 0), northdirection=0):
+    def __init__(self, texturepath=None, bgcolor=(26, 26, 26, 0), northdirection=0, customblocks=None):
         self.bgcolor = bgcolor
         self.rotation = northdirection
         self.find_file_local_path = texturepath
-        
+        self.customblocks = customblocks
+
         # not yet configurable
         self.texture_size = 24
         self.texture_dimensions = (self.texture_size, self.texture_size)
@@ -100,7 +101,11 @@ def generate(self):
                 block = tex[0]
                 scaled_block = block.resize(self.texture_dimensions, Image.ANTIALIAS)
                 blockmap[i] = self.generate_texture_tuple(scaled_block)
-        
+
+        if not self.customblocks is None:
+            for i in self.customblocks:
+                execfile(i)
+
         self.generated = True
     
     ##
@@ -1304,43 +1309,6 @@ def tall_grass(self, blockid, data):
 # dead bush
 billboard(blockid=32, index=55)
 
-@material(blockid=35, data=range(16), solid=True)
-def wool(self, blockid, data):
-    if data == 0: # white
-        texture = self.terrain_images[64]
-    elif data == 1: # orange
-        texture = self.terrain_images[210]
-    elif data == 2: # magenta
-        texture = self.terrain_images[194]
-    elif data == 3: # light blue
-        texture = self.terrain_images[178]
-    elif data == 4: # yellow
-        texture = self.terrain_images[162]
-    elif data == 5: # light green
-        texture = self.terrain_images[146]
-    elif data == 6: # pink
-        texture = self.terrain_images[130]
-    elif data == 7: # grey
-        texture = self.terrain_images[114]
-    elif data == 8: # light grey
-        texture = self.terrain_images[225]
-    elif data == 9: # cyan
-        texture = self.terrain_images[209]
-    elif data == 10: # purple
-        texture = self.terrain_images[193]
-    elif data == 11: # blue
-        texture = self.terrain_images[177]
-    elif data == 12: # brown
-        texture = self.terrain_images[161]
-    elif data == 13: # dark green
-        texture = self.terrain_images[145]
-    elif data == 14: # red
-        texture = self.terrain_images[129]
-    elif data == 15: # black
-        texture = self.terrain_images[113]
-    
-    return self.build_block(texture, texture)
-
 # dandelion
 sprite(blockid=37, index=13)
 # rose