diff --git a/docs/export-map.rst b/docs/export-map.rst
index 449187dff..11d1b87fb 100644
--- a/docs/export-map.rst
+++ b/docs/export-map.rst
@@ -87,7 +87,12 @@ Options
     TOPAZOLITE/BLACK_OPAL/etc.) (will return nil if the tile is empty)
 
 ``-u``, ``--underworld``
-    Whether the underworld z-levels will be included [boolean]
+    Whether the underworld z-levels will be included
+
+``-e``, ``--evilness``
+    Whether the evilness value will be included in MAP_SIZE table. This only
+    checks the value of the center map tile at ground level and will ignore
+    biomes at the edges of the map.
 
 JSON DATA
 ---------
diff --git a/export-map.lua b/export-map.lua
index f0706542e..4eff32cbf 100644
--- a/export-map.lua
+++ b/export-map.lua
@@ -10,6 +10,7 @@ local argparse = require('argparse')
 
 local include_underworld_z = false
 local underworld_z
+local evilness
 
 -- the layer of the underworld
 for _, feature in ipairs(df.global.world.features.map_features) do
@@ -18,6 +19,21 @@ for _, feature in ipairs(df.global.world.features.map_features) do
     end
 end
 
+-- copied from agitation-rebalance.lua
+-- check only one tile at the center of the map at ground lvl
+-- (this ignore different biomes on the edges of the map)
+local function get_evilness()
+    -- check around ground level
+    local lvls_above_ground = world.worldgen.worldgen_parms.levels_above_ground
+    local ground_z = (world.map.z_count - 2) - lvls_above_ground
+    local xmax, ymax = dfhack.maps.getTileSize()
+    local center_x, center_y = math.floor(xmax/2), math.floor(ymax/2)
+    local rgnX, rgnY = dfhack.maps.getTileBiomeRgn(center_x, center_y, ground_z)
+    local biome = dfhack.maps.getRegionBiome(rgnX, rgnY)
+
+    return biome and biome.evilness or 0
+end
+
 local function classify_tile(options, x, y, z)
     -- The last z-levels of hell shrink their x/y size unexpectedly! (ಠ_ಠ)
     -- if your map is 190x190, the last hell z-levels are gonna be like 90x90
@@ -155,6 +171,7 @@ local function export_all_z_levels(fortress_name, folder, options)
         -- subtract underworld levels if excluded from options
         z = include_underworld_z and zmax or (zmax - underworld_z),
         underworld_z_level = include_underworld_z and underworld_z or nil,
+        evilness = evilness or nil,
     }
     data.KEYS = setup_keys(options)
 
@@ -230,7 +247,8 @@ local positionals = argparse.processArgsGetopt(args, {
     {'a', 'aquifer', handler=function() options.aquifer = true end},
     {'m', 'material', handler=function() options.material = true end},
     -- local var since underworld not in ordered option
-    {'u', 'underworld', handler= function() include_underworld_z = true end},
+    {'u', 'underworld', handler=function() include_underworld_z = true end},
+    {'e', 'evilness', handler=function() evilness = get_evilness() end},
 })
 
 if positionals[1] == "help" or options.help then