diff --git a/pkg/model/openstackmodel/servergroup.go b/pkg/model/openstackmodel/servergroup.go
index 849c3b1653685..a920d9870f1bf 100644
--- a/pkg/model/openstackmodel/servergroup.go
+++ b/pkg/model/openstackmodel/servergroup.go
@@ -218,11 +218,17 @@ func (b *ServerGroupModelBuilder) Build(c *fi.ModelBuilderContext) error {
 	var masters []*openstacktasks.ServerGroup
 	for _, ig := range b.InstanceGroups {
 		klog.V(2).Infof("Found instance group with name %s and role %v.", ig.Name, ig.Spec.Role)
+		affinityPolicies := []string{}
+		if v, ok := ig.ObjectMeta.Annotations[openstack.OS_ANNOTATION+openstack.SERVER_GROUP_AFFINITY]; ok {
+			affinityPolicies = append(affinityPolicies, v)
+		} else {
+			affinityPolicies = append(affinityPolicies, "anti-affinity")
+		}
 		sgTask := &openstacktasks.ServerGroup{
 			Name:        s(fmt.Sprintf("%s-%s", clusterName, ig.Name)),
 			ClusterName: s(clusterName),
 			IGName:      s(ig.Name),
-			Policies:    []string{"anti-affinity"},
+			Policies:    affinityPolicies,
 			Lifecycle:   b.Lifecycle,
 			MaxSize:     ig.Spec.MaxSize,
 		}
diff --git a/pkg/model/openstackmodel/servergroup_test.go b/pkg/model/openstackmodel/servergroup_test.go
index 33828351ce500..57547f427d7e0 100644
--- a/pkg/model/openstackmodel/servergroup_test.go
+++ b/pkg/model/openstackmodel/servergroup_test.go
@@ -948,6 +948,45 @@ func getServerGroupModelBuilderTestInput() []serverGroupModelBuilderTestInput {
 				},
 			},
 		},
+		{
+			desc: "configures server group affinity with annotations",
+			cluster: &kops.Cluster{
+				ObjectMeta: metav1.ObjectMeta{
+					Name: "cluster",
+				},
+				Spec: kops.ClusterSpec{
+					MasterPublicName: "master-public-name",
+					CloudConfig: &kops.CloudConfiguration{
+						Openstack: &kops.OpenstackConfiguration{},
+					},
+					Subnets: []kops.ClusterSubnetSpec{
+						{
+							Name:   "subnet",
+							Region: "region",
+						},
+					},
+				},
+			},
+			instanceGroups: []*kops.InstanceGroup{
+				{
+					ObjectMeta: metav1.ObjectMeta{
+						Name: "node",
+						Annotations: map[string]string{
+							"openstack.kops.io/serverGroupAffinity": "soft-anti-affinity",
+						},
+					},
+					Spec: kops.InstanceGroupSpec{
+						Role:        kops.InstanceGroupRoleNode,
+						Image:       "image-node",
+						MinSize:     i32(1),
+						MaxSize:     i32(1),
+						MachineType: "blc.2-4",
+						Subnets:     []string{"subnet"},
+						Zones:       []string{"zone-1"},
+					},
+				},
+			},
+		},
 	}
 }
 
diff --git a/pkg/model/openstackmodel/tests/servergroup/configures-server-group-affinity-with-annotations.yaml b/pkg/model/openstackmodel/tests/servergroup/configures-server-group-affinity-with-annotations.yaml
new file mode 100644
index 0000000000000..160fd60441180
--- /dev/null
+++ b/pkg/model/openstackmodel/tests/servergroup/configures-server-group-affinity-with-annotations.yaml
@@ -0,0 +1,111 @@
+Name: node
+---
+AvailabilityZone: zone-1
+Flavor: blc.2-4
+FloatingIP: null
+ForAPIServer: false
+GroupName: node
+ID: null
+Image: image-node
+Lifecycle: null
+Metadata:
+  KopsInstanceGroup: node
+  KopsName: node-1-cluster
+  KopsNetwork: cluster
+  KopsRole: Node
+  KubernetesCluster: cluster
+  cluster_generation: "0"
+  ig_generation: "0"
+  k8s: cluster
+  k8s.io_cluster-autoscaler_node-template_label_kubernetes.io_role: node
+  k8s.io_cluster-autoscaler_node-template_label_node-role.kubernetes.io_node: ""
+  k8s.io_role_node: "1"
+  kops.k8s.io_instancegroup: node
+Name: node-1-cluster
+Port:
+  AdditionalSecurityGroups: null
+  ID: null
+  Lifecycle: Sync
+  Name: port-node-1-cluster
+  Network:
+    AvailabilityZoneHints: null
+    ID: null
+    Lifecycle: null
+    Name: cluster
+    Tag: null
+  SecurityGroups:
+  - Description: null
+    ID: null
+    Lifecycle: null
+    Name: nodes.cluster
+    RemoveExtraRules: null
+    RemoveGroup: false
+  Subnets:
+  - CIDR: null
+    DNSServers: null
+    ID: null
+    Lifecycle: null
+    Name: subnet.cluster
+    Network: null
+    Tag: null
+  Tag: cluster
+Region: region
+Role: Node
+SSHKey: kubernetes.cluster-ba_d8_85_a0_5b_50_b0_01_e0_b2_b0_ae_5d_f6_7a_d1
+SecurityGroups: null
+ServerGroup:
+  ClusterName: cluster
+  ID: null
+  IGName: node
+  Lifecycle: Sync
+  MaxSize: 1
+  Name: cluster-node
+  Policies:
+  - soft-anti-affinity
+UserData:
+  task:
+    Name: node
+---
+Lifecycle: null
+Name: ca
+Signer: null
+alternateNames: null
+oldFormat: false
+subject: cn=kubernetes
+type: ca
+---
+AdditionalSecurityGroups: null
+ID: null
+Lifecycle: Sync
+Name: port-node-1-cluster
+Network:
+  AvailabilityZoneHints: null
+  ID: null
+  Lifecycle: null
+  Name: cluster
+  Tag: null
+SecurityGroups:
+- Description: null
+  ID: null
+  Lifecycle: null
+  Name: nodes.cluster
+  RemoveExtraRules: null
+  RemoveGroup: false
+Subnets:
+- CIDR: null
+  DNSServers: null
+  ID: null
+  Lifecycle: null
+  Name: subnet.cluster
+  Network: null
+  Tag: null
+Tag: cluster
+---
+ClusterName: cluster
+ID: null
+IGName: node
+Lifecycle: Sync
+MaxSize: 1
+Name: cluster-node
+Policies:
+- soft-anti-affinity
diff --git a/upup/pkg/fi/cloudup/openstack/instance.go b/upup/pkg/fi/cloudup/openstack/instance.go
index 259a9706cde23..4c06761730c5f 100644
--- a/upup/pkg/fi/cloudup/openstack/instance.go
+++ b/upup/pkg/fi/cloudup/openstack/instance.go
@@ -39,6 +39,7 @@ const (
 	OS_ANNOTATION             = "openstack.kops.io/"
 	BOOT_FROM_VOLUME          = "osVolumeBoot"
 	BOOT_VOLUME_SIZE          = "osVolumeSize"
+	SERVER_GROUP_AFFINITY     = "serverGroupAffinity"
 )
 
 // floatingBackoff is the backoff strategy for listing openstack floatingips