diff --git a/init.lua b/init.lua
index 1ab9b3b..4dbbfb6 100644
--- a/init.lua
+++ b/init.lua
@@ -1,4 +1,27 @@
-nssm = {}
+nssm = {
+    version = "20190117",
+    maintainer = "taikedz-mt", -- change if forking project
+}
+
+-- Pre-check compatibility
+--  Downloaded
+
+local mobs_version_required = 20181220
+
+if mobs then
+    if not (mobs.version and mobs.version > mobs_version_required) then
+        minetest.log("error",
+            "Incompatible mobs library (version "..
+            tostring(mobs.version)..
+            ") loaded. Please use a recent mobs_redo (newer than"..
+            mobs_version_required..")"
+        )
+        os.exit(1) -- Bail early, mainly for servers.
+    end
+else
+    minetest.log("error", "No mobs engine detected. Please use mobs_redo -> https://tinyurl.com/mt-mobs-redo .")
+    os.exit(1)
+end
 
 -- File loading
 nssm.path = minetest.get_modpath("nssm")
diff --git a/tools/bomb_evocation.lua b/tools/bomb_evocation.lua
index df876f0..9f7b812 100644
--- a/tools/bomb_evocation.lua
+++ b/tools/bomb_evocation.lua
@@ -1,4 +1,4 @@
-function nssm_register_evocation (evomob, evodescr, numbe)
+function nssm_register_evocation (evomob, evodescr, numbe, evomob_ingredient)
     nssm_register_throwegg(evomob, evodescr.." Bomb", {
         hit_node = function(self,pos)
                         local pos1 = {x = pos.x, y=pos.y+1, z=pos.z}
@@ -13,7 +13,7 @@ function nssm_register_evocation (evomob, evodescr, numbe)
     minetest.register_craft({
         output = 'nssm:'..evomob.."_bomb",
         type = "shapeless",
-        recipe = {'nssm:empty_evocation_bomb', 'nssm:'..evomob},
+        recipe = {'nssm:empty_evocation_bomb', 'nssm:'..(evomob_ingredient or evomob)},
 
     })
 end
@@ -23,6 +23,6 @@ nssm_register_evocation ("bloco","Bloco Evocation", 3)
 nssm_register_evocation ("enderduck","Enderduck Evocation", 2)
 nssm_register_evocation ("flying_duck","Flying Duck Evocation", 3)
 nssm_register_evocation ("swimming_duck","Swimming Duck Evocation", 3)
-nssm_register_evocation ("duckking","Duckking Evocation", 1)
+nssm_register_evocation ("duckking","Duckking Evocation", 1, "duckking_egg")
 nssm_register_evocation ("spiderduck","Spiderduck Evocation", 2)