diff --git a/README.md b/README.md
index 4462274..62ce152 100644
--- a/README.md
+++ b/README.md
@@ -53,6 +53,9 @@ This mod has strict error checking, so bad strings will not crash your game or m
 
 ####Changelog
 
+Version 3.1.2
+- Fixed constant combinators from 0.12 blueprints
+
 Version 3.1.1
 - Toned down the 0.12.32 upgrade button
 
diff --git a/blueprintstring/blueprintstring.lua b/blueprintstring/blueprintstring.lua
index e520f63..4bc90be 100644
--- a/blueprintstring/blueprintstring.lua
+++ b/blueprintstring/blueprintstring.lua
@@ -87,6 +87,9 @@ function fix_entities(array)
 					entity.control_behavior = {decider_conditions = entity.conditions.decider}
 				end
 			end
+			if (entity.name == "constant-combinator" and entity.filters) then
+				entity.control_behavior = {filters = entity.filters}
+			end
 
 			-- Add entity number
 			entity.entity_number = count
diff --git a/control.lua b/control.lua
index e2355f0..d74eb90 100644
--- a/control.lua
+++ b/control.lua
@@ -242,6 +242,8 @@ function load_blueprint(player)
 
 	local blueprint = nil
 	local book = nil
+	local active = nil
+	local main = nil
 	if (not blueprint_format.book) then
 		-- Blueprint
 		if (holding_book(player)) then
@@ -284,8 +286,8 @@ function load_blueprint(player)
 			return
 		end
 
-		local active = book.get_inventory(defines.inventory.item_active)
-		local main = book.get_inventory(defines.inventory.item_main)
+		active = book.get_inventory(defines.inventory.item_active)
+		main = book.get_inventory(defines.inventory.item_main)
 
 		local advanced_circuits = slots - active.get_item_count("blueprint") - main.get_item_count("blueprint")
 		if (advanced_circuits > player.get_item_count("advanced-circuit")) then
@@ -327,6 +329,7 @@ function load_blueprint(player)
 
 	textbox.text = ""
 
+	-- Blueprint
 	if (not book) then
 		local error = load_blueprint_data(blueprint, blueprint_format)
 		if (error) then
@@ -335,22 +338,21 @@ function load_blueprint(player)
 		return
 	end
 	
-	for i, page in pairs(blueprint_format.book) do
-		local active = book.get_inventory(defines.inventory.item_active)
-		local main = book.get_inventory(defines.inventory.item_main)
-		local error
-		if (i == 1) then
-			error = load_blueprint_data(active[1], page)
-		else
-			if (i - 1 > #main) then
-				break
-			end
-			error = load_blueprint_data(main[i-1], page)
-		end
+	-- Blueprint Book
+	if (blueprint_format.book[1]) then
+		local error = load_blueprint_data(active[1], blueprint_format.book[1])
 		if (error and error[1] ~= "unknown-format") then
 			player.print(error)
 		end
 	end
+	for i = 1, #main do
+		if (blueprint_format.book[i+1]) then
+			local error = load_blueprint_data(main[i], blueprint_format.book[i+1])
+			if (error and error[1] ~= "unknown-format") then
+				player.print(error)
+			end
+		end
+	end
 	book.label = blueprint_format.name or ""
 end
 
diff --git a/info.json b/info.json
index 868ccb2..22fb2a4 100644
--- a/info.json
+++ b/info.json
@@ -1,6 +1,6 @@
 {
   "name": "blueprint-string",
-  "version": "3.1.1",
+  "version": "3.1.2",
   "title": "Blueprint String",
   "author": "DaveMcW",
   "description": "Converts text strings into blueprints",
diff --git a/locale/en/blueprint-string.cfg b/locale/en/blueprint-string.cfg
index ab8fdce..f589805 100644
--- a/locale/en/blueprint-string.cfg
+++ b/locale/en/blueprint-string.cfg
@@ -1,3 +1,4 @@
+main-button=Blueprint
 save=Save
 save-as=Save as:
 cancel=Cancel