diff --git a/senza/components/elastigroup.py b/senza/components/elastigroup.py
index 59e015a9..38e87ffe 100644
--- a/senza/components/elastigroup.py
+++ b/senza/components/elastigroup.py
@@ -51,7 +51,7 @@ def component_elastigroup(definition, configuration, args, info, force, account_
     ensure_default_product(elastigroup_config)
     ensure_instance_monitoring(elastigroup_config)
 
-    extract_subnets(definition, elastigroup_config, account_info)
+    extract_subnets(configuration, elastigroup_config, account_info)
     extract_user_data(configuration, elastigroup_config, info, force, account_info)
     extract_load_balancer_name(configuration, elastigroup_config)
     extract_public_ips(configuration, elastigroup_config)
@@ -264,7 +264,7 @@ def fill_standard_tags(definition, elastigroup_config):
         elastigroup_config["name"] = full_name
 
 
-def extract_subnets(definition, elastigroup_config, account_info):
+def extract_subnets(configuration, elastigroup_config, account_info):
     """
     This fills in the subnetIds and region attributes of the Spotinst elastigroup, in case they're not defined already
     The subnetIds are discovered by Senza::StupsAutoConfiguration and the region is provided by the AccountInfo object
@@ -273,9 +273,9 @@ def extract_subnets(definition, elastigroup_config, account_info):
     subnet_ids = elastigroup_config["compute"].get("subnetIds", [])
     target_region = elastigroup_config.get("region", account_info.Region)
     if not subnet_ids:
-        subnet_ids = definition["Mappings"]["ServerSubnets"].get(target_region, {}).get("Subnets", [])
+        subnet_set = "LoadBalancerSubnets" if configuration.get("AssociatePublicIpAddress", False) else "ServerSubnets"
+        elastigroup_config["compute"]["subnetIds"] = {"Fn::FindInMap": [subnet_set, {"Ref": "AWS::Region"}, "Subnets"]}
     elastigroup_config["region"] = target_region
-    elastigroup_config["compute"]["subnetIds"] = subnet_ids
 
 
 def extract_user_data(configuration, elastigroup_config, info: dict, force, account_info):
diff --git a/tests/test_elastigroup.py b/tests/test_elastigroup.py
index 41f98f58..30344be7 100644
--- a/tests/test_elastigroup.py
+++ b/tests/test_elastigroup.py
@@ -62,7 +62,7 @@ def test_component_elastigroup_defaults(monkeypatch):
     assert {'tagKey': 'StackName', 'tagValue': 'foobar'} in tags
     assert {'tagKey': 'StackVersion', 'tagValue': '0.1'} in tags
     assert properties["group"]["compute"]["product"] == ELASTIGROUP_DEFAULT_PRODUCT
-    assert properties["group"]["compute"]["subnetIds"] == subnets
+    assert properties["group"]["compute"]["subnetIds"] == {"Fn::FindInMap": ["ServerSubnets", {"Ref": "AWS::Region"}, "Subnets"]}
     assert properties["group"]["region"] == "reg1"
     assert properties["group"]["strategy"] == ELASTIGROUP_DEFAULT_STRATEGY
 
@@ -381,21 +381,22 @@ def test_standard_tags():
 
 def test_extract_subnets():
     test_cases = [
-        {  # use auto discovered subnets from auto-discovered region
-            "definition": {"Mappings": {"ServerSubnets": {"reg1": {"Subnets": ["sn1", "sn2"]}}}},
+        {  # use auto discovered server subnets
+            "component_config": {},
             "given_config": {},
-            "expected_config": {"compute": {"subnetIds": ["sn1", "sn2"]}, "region": "reg1"},
+            "expected_config": {
+                "compute": {"subnetIds": {"Fn::FindInMap": ["ServerSubnets", {"Ref": "AWS::Region"}, "Subnets"]}},
+                "region": "reg1"},
         },
-        {  # use auto discovered subnets from specified region
-            "definition": {"Mappings": {"ServerSubnets": {
-                "reg1": {"Subnets": ["sn1", "sn2"]},
-                "reg2": {"Subnets": ["n1", "n2"]}
-            }}},
-            "given_config": {"region": "reg2"},
-            "expected_config": {"compute": {"subnetIds": ["n1", "n2"]}, "region": "reg2"},
+        {  # use auto discovered DMZ subnets
+            "component_config": {"AssociatePublicIpAddress": True},
+            "given_config": {},
+            "expected_config": {
+                "compute": {"subnetIds": {"Fn::FindInMap": ["LoadBalancerSubnets", {"Ref": "AWS::Region"}, "Subnets"]}},
+                "region": "reg1"},
         },
         {  # leave subnetIds untouched
-            "definition": {"Mappings": {"ServerSubnets": {"reg1": {"Subnets": ["sn1", "sn2"]}}}},
+            "component_config": {},
             "given_config": {"compute": {"subnetIds": ["subnet01"]}},
             "expected_config": {"compute": {"subnetIds": ["subnet01"]}, "region": "reg1"},
         },
@@ -403,9 +404,10 @@ def test_extract_subnets():
     account_info = MagicMock()
     account_info.Region = "reg1"
     for test_case in test_cases:
-        got = test_case["given_config"]
-        extract_subnets(test_case["definition"], got, account_info)
-        assert test_case["expected_config"] == got
+        input = test_case["given_config"]
+        config = test_case["component_config"]
+        extract_subnets(config, input, account_info)
+        assert test_case["expected_config"] == input
 
 
 def test_load_balancers():