diff --git a/mods/CORE/_mcl_autogroup/init.lua b/mods/CORE/_mcl_autogroup/init.lua
index e04fb2eac..528832856 100644
--- a/mods/CORE/_mcl_autogroup/init.lua
+++ b/mods/CORE/_mcl_autogroup/init.lua
@@ -348,6 +348,12 @@ local function overwrite()
 				groups = newgroups
 			})
 		end
+		--
+		if nname ~= "ignore" and ndef.light_source == nil or ndef.light_source < 2 then
+			minetest.override_item(nname, {
+				light_source = 2
+			})
+		end
 	end
 
 	for tname, tdef in pairs(minetest.registered_tools) do