diff --git a/data/json/monstergroups/zombie_upgrades.json b/data/json/monstergroups/zombie_upgrades.json
index 4228ce1b735d..651b86e6c134 100644
--- a/data/json/monstergroups/zombie_upgrades.json
+++ b/data/json/monstergroups/zombie_upgrades.json
@@ -27,13 +27,11 @@
       { "monster": "mon_zombie_biter", "freq": 15, "cost_multiplier": 5 },
       { "monster": "mon_zombie_shrieker", "freq": 45, "cost_multiplier": 5 },
       { "monster": "mon_zombie_acidic", "freq": 45, "cost_multiplier": 2 },
-      { "monster": "mon_zombie_necro", "freq": 8, "cost_multiplier": 25 },
       { "monster": "mon_boomer", "freq": 45, "cost_multiplier": 5 },
       { "monster": "mon_zombie_brute", "freq": 23, "cost_multiplier": 15 },
-      { "monster": "mon_zombie_master", "freq": 2, "cost_multiplier": 30 },
-      { "monster": "mon_zombie_hollow", "freq": 3, "cost_multiplier": 10 },
       { "monster": "mon_zombie_thorny", "freq": 13, "cost_multiplier": 5 },
-      { "monster": "mon_zombie_nurse", "freq": 10, "cost_multiplier": 3 }
+      { "monster": "mon_zombie_nurse", "freq": 10, "cost_multiplier": 3 },
+      { "monster": "mon_zombie_hollow", "freq": 3, "cost_multiplier": 10 }
     ]
   },
   {
diff --git a/data/json/monsters/zed_misc.json b/data/json/monsters/zed_misc.json
index 3e730f0d95b0..5dba8b52036b 100644
--- a/data/json/monsters/zed_misc.json
+++ b/data/json/monsters/zed_misc.json
@@ -428,6 +428,7 @@
     "harvest": "zombie",
     "special_attacks": [ [ "STRETCH_BITE", 10 ], [ "STRETCH_ATTACK", 5 ] ],
     "death_function": [ "BLOBSPLIT" ],
+    "upgrades": { "half_life": 30, "into": "mon_zombie_necro" },
     "flags": [ "SEES", "HEARS", "SMELLS", "WARM", "BASHES", "GROUP_BASH", "POISON", "NO_BREATHE", "FILTHY" ]
   },
   {
@@ -649,6 +650,7 @@
     "death_drops": "default_zombie_death_drops",
     "death_function": [ "NORMAL" ],
     "burn_into": "mon_zombie_scorched",
+    "upgrades": { "half_life": 15, "into": "mon_zombie_hollow" },
     "flags": [
       "SEES",
       "HEARS",
@@ -697,6 +699,7 @@
     "death_drops": "default_zombie_death_drops",
     "death_function": [ "NORMAL" ],
     "burn_into": "mon_zombie_scorched",
+    "upgrades": { "half_life": 60, "into": "mon_zombie_master" },
     "flags": [
       "SEES",
       "HEARS",