diff --git a/changelog.txt b/changelog.txt
index 7e96675..9eb2137 100644
--- a/changelog.txt
+++ b/changelog.txt
@@ -1,4 +1,10 @@
 ---------------------------------------------------------------------------------------------------
+Version: 0.5.0
+Date: 2021-01-07
+  Changes:
+    - Zircon used instead of iron ore in concrete (use Bypass recipes if you wish)
+    - Zirconium processing no longer a prerequisite to chemical science
+---------------------------------------------------------------------------------------------------
 Version: 0.4.4
 Date: 2021-01-07
   Changes:
diff --git a/info.json b/info.json
index ce7c031..edf09f9 100644
--- a/info.json
+++ b/info.json
@@ -1,6 +1,6 @@
 {
     "name": "bzzirconium",
-    "version": "0.4.4",
+    "version": "0.5.0",
     "factorio_version": "1.1",
     "title": "Zirconium",
     "author": "Brevven",
diff --git a/tech-updates.lua b/tech-updates.lua
index fa146d0..af981c0 100644
--- a/tech-updates.lua
+++ b/tech-updates.lua
@@ -4,7 +4,6 @@ util.add_prerequisite("advanced-material-processing-2", "zirconia-processing")
 util.add_prerequisite("low-density-structure", "zirconia-processing")
 util.add_prerequisite("nuclear-power", "zirconia-processing")
 util.add_prerequisite("explosives", "zirconia-processing")
-util.add_prerequisite("chemical-science-pack", "zirconia-processing")
 
 if util.me.use_cermet() then
   -- production science techs behind cermet
diff --git a/zirconium-recipe-updates.lua b/zirconium-recipe-updates.lua
index 86965eb..48e0974 100644
--- a/zirconium-recipe-updates.lua
+++ b/zirconium-recipe-updates.lua
@@ -9,6 +9,11 @@ if not mods["Krastorio2"] then
   util.replace_some_ingredient("electric-furnace", "stone-brick", 5, "zirconia", 5)
 end
 
+util.replace_ingredient("concrete", "iron-ore", "zircon")
+if mods["aai-industry"] then
+  util.add_ingredient("concrete", "zircon", 1)
+end
+
 if mods["Krastorio2"] then
   util.replace_some_ingredient("low-density-structure", "copper-plate", 5, "zirconia", 5)
 else