diff --git a/tests/integration/update_cluster/ha_gce/kubernetes.tf b/tests/integration/update_cluster/ha_gce/kubernetes.tf
index 3703551febde9..a60851a05602d 100644
--- a/tests/integration/update_cluster/ha_gce/kubernetes.tf
+++ b/tests/integration/update_cluster/ha_gce/kubernetes.tf
@@ -501,8 +501,9 @@ resource "google_compute_instance_group_manager" "a-master-us-test1-a-ha-gce-exa
   name                           = "a-master-us-test1-a-ha-gce-example-com"
   target_size                    = 1
   update_policy {
-    minimal_action = "REPLACE"
-    type           = "OPPORTUNISTIC"
+    max_unavailable_fixed = 1
+    minimal_action        = "REPLACE"
+    type                  = "OPPORTUNISTIC"
   }
   version {
     instance_template = google_compute_instance_template.master-us-test1-a-ha-gce-example-com.self_link
@@ -519,8 +520,9 @@ resource "google_compute_instance_group_manager" "a-nodes-ha-gce-example-com" {
   name                           = "a-nodes-ha-gce-example-com"
   target_size                    = 1
   update_policy {
-    minimal_action = "REPLACE"
-    type           = "OPPORTUNISTIC"
+    max_unavailable_fixed = 1
+    minimal_action        = "REPLACE"
+    type                  = "OPPORTUNISTIC"
   }
   version {
     instance_template = google_compute_instance_template.nodes-ha-gce-example-com.self_link
@@ -537,8 +539,9 @@ resource "google_compute_instance_group_manager" "b-master-us-test1-b-ha-gce-exa
   name                           = "b-master-us-test1-b-ha-gce-example-com"
   target_size                    = 1
   update_policy {
-    minimal_action = "REPLACE"
-    type           = "OPPORTUNISTIC"
+    max_unavailable_fixed = 1
+    minimal_action        = "REPLACE"
+    type                  = "OPPORTUNISTIC"
   }
   version {
     instance_template = google_compute_instance_template.master-us-test1-b-ha-gce-example-com.self_link
@@ -555,8 +558,9 @@ resource "google_compute_instance_group_manager" "b-nodes-ha-gce-example-com" {
   name                           = "b-nodes-ha-gce-example-com"
   target_size                    = 1
   update_policy {
-    minimal_action = "REPLACE"
-    type           = "OPPORTUNISTIC"
+    max_unavailable_fixed = 1
+    minimal_action        = "REPLACE"
+    type                  = "OPPORTUNISTIC"
   }
   version {
     instance_template = google_compute_instance_template.nodes-ha-gce-example-com.self_link
@@ -573,8 +577,9 @@ resource "google_compute_instance_group_manager" "c-master-us-test1-c-ha-gce-exa
   name                           = "c-master-us-test1-c-ha-gce-example-com"
   target_size                    = 1
   update_policy {
-    minimal_action = "REPLACE"
-    type           = "OPPORTUNISTIC"
+    max_unavailable_fixed = 1
+    minimal_action        = "REPLACE"
+    type                  = "OPPORTUNISTIC"
   }
   version {
     instance_template = google_compute_instance_template.master-us-test1-c-ha-gce-example-com.self_link
@@ -591,8 +596,9 @@ resource "google_compute_instance_group_manager" "c-nodes-ha-gce-example-com" {
   name                           = "c-nodes-ha-gce-example-com"
   target_size                    = 0
   update_policy {
-    minimal_action = "REPLACE"
-    type           = "OPPORTUNISTIC"
+    max_unavailable_fixed = 1
+    minimal_action        = "REPLACE"
+    type                  = "OPPORTUNISTIC"
   }
   version {
     instance_template = google_compute_instance_template.nodes-ha-gce-example-com.self_link
diff --git a/tests/integration/update_cluster/many-addons-gce/kubernetes.tf b/tests/integration/update_cluster/many-addons-gce/kubernetes.tf
index 88489af93399a..c2dc0a7905bec 100644
--- a/tests/integration/update_cluster/many-addons-gce/kubernetes.tf
+++ b/tests/integration/update_cluster/many-addons-gce/kubernetes.tf
@@ -429,8 +429,9 @@ resource "google_compute_instance_group_manager" "a-master-us-test1-a-minimal-ex
   name                           = "a-master-us-test1-a-minimal-example-com"
   target_size                    = 1
   update_policy {
-    minimal_action = "REPLACE"
-    type           = "OPPORTUNISTIC"
+    max_unavailable_fixed = 1
+    minimal_action        = "REPLACE"
+    type                  = "OPPORTUNISTIC"
   }
   version {
     instance_template = google_compute_instance_template.master-us-test1-a-minimal-example-com.self_link
@@ -447,8 +448,9 @@ resource "google_compute_instance_group_manager" "a-nodes-minimal-example-com" {
   name                           = "a-nodes-minimal-example-com"
   target_size                    = 1
   update_policy {
-    minimal_action = "REPLACE"
-    type           = "OPPORTUNISTIC"
+    max_unavailable_fixed = 1
+    minimal_action        = "REPLACE"
+    type                  = "OPPORTUNISTIC"
   }
   version {
     instance_template = google_compute_instance_template.nodes-minimal-example-com.self_link
diff --git a/tests/integration/update_cluster/minimal_gce/kubernetes.tf b/tests/integration/update_cluster/minimal_gce/kubernetes.tf
index 5e7f4132ff5c8..683e88075db7f 100644
--- a/tests/integration/update_cluster/minimal_gce/kubernetes.tf
+++ b/tests/integration/update_cluster/minimal_gce/kubernetes.tf
@@ -397,8 +397,9 @@ resource "google_compute_instance_group_manager" "a-master-us-test1-a-minimal-gc
   name                           = "a-master-us-test1-a-minimal-gce-example-com"
   target_size                    = 1
   update_policy {
-    minimal_action = "REPLACE"
-    type           = "OPPORTUNISTIC"
+    max_unavailable_fixed = 1
+    minimal_action        = "REPLACE"
+    type                  = "OPPORTUNISTIC"
   }
   version {
     instance_template = google_compute_instance_template.master-us-test1-a-minimal-gce-example-com.self_link
@@ -415,8 +416,9 @@ resource "google_compute_instance_group_manager" "a-nodes-minimal-gce-example-co
   name                           = "a-nodes-minimal-gce-example-com"
   target_size                    = 1
   update_policy {
-    minimal_action = "REPLACE"
-    type           = "OPPORTUNISTIC"
+    max_unavailable_fixed = 1
+    minimal_action        = "REPLACE"
+    type                  = "OPPORTUNISTIC"
   }
   version {
     instance_template = google_compute_instance_template.nodes-minimal-gce-example-com.self_link
@@ -433,8 +435,9 @@ resource "google_compute_instance_group_manager" "b-nodes-minimal-gce-example-co
   name                           = "b-nodes-minimal-gce-example-com"
   target_size                    = 1
   update_policy {
-    minimal_action = "REPLACE"
-    type           = "OPPORTUNISTIC"
+    max_unavailable_fixed = 1
+    minimal_action        = "REPLACE"
+    type                  = "OPPORTUNISTIC"
   }
   version {
     instance_template = google_compute_instance_template.nodes-minimal-gce-example-com.self_link
diff --git a/tests/integration/update_cluster/minimal_gce_dns-none/kubernetes.tf b/tests/integration/update_cluster/minimal_gce_dns-none/kubernetes.tf
index c9f3c7ba2c1ab..cb15a40223953 100644
--- a/tests/integration/update_cluster/minimal_gce_dns-none/kubernetes.tf
+++ b/tests/integration/update_cluster/minimal_gce_dns-none/kubernetes.tf
@@ -469,8 +469,9 @@ resource "google_compute_instance_group_manager" "a-master-us-test1-a-minimal-gc
   name                           = "a-master-us-test1-a-minimal-gce-example-com"
   target_size                    = 1
   update_policy {
-    minimal_action = "REPLACE"
-    type           = "OPPORTUNISTIC"
+    max_unavailable_fixed = 1
+    minimal_action        = "REPLACE"
+    type                  = "OPPORTUNISTIC"
   }
   version {
     instance_template = google_compute_instance_template.master-us-test1-a-minimal-gce-example-com.self_link
@@ -487,8 +488,9 @@ resource "google_compute_instance_group_manager" "a-nodes-minimal-gce-example-co
   name                           = "a-nodes-minimal-gce-example-com"
   target_size                    = 1
   update_policy {
-    minimal_action = "REPLACE"
-    type           = "OPPORTUNISTIC"
+    max_unavailable_fixed = 1
+    minimal_action        = "REPLACE"
+    type                  = "OPPORTUNISTIC"
   }
   version {
     instance_template = google_compute_instance_template.nodes-minimal-gce-example-com.self_link
@@ -505,8 +507,9 @@ resource "google_compute_instance_group_manager" "b-nodes-minimal-gce-example-co
   name                           = "b-nodes-minimal-gce-example-com"
   target_size                    = 1
   update_policy {
-    minimal_action = "REPLACE"
-    type           = "OPPORTUNISTIC"
+    max_unavailable_fixed = 1
+    minimal_action        = "REPLACE"
+    type                  = "OPPORTUNISTIC"
   }
   version {
     instance_template = google_compute_instance_template.nodes-minimal-gce-example-com.self_link
diff --git a/tests/integration/update_cluster/minimal_gce_ilb/kubernetes.tf b/tests/integration/update_cluster/minimal_gce_ilb/kubernetes.tf
index b5964667b2012..6ef9c2927a310 100644
--- a/tests/integration/update_cluster/minimal_gce_ilb/kubernetes.tf
+++ b/tests/integration/update_cluster/minimal_gce_ilb/kubernetes.tf
@@ -438,8 +438,9 @@ resource "google_compute_instance_group_manager" "a-master-us-test1-a-minimal-gc
   name                           = "a-master-us-test1-a-minimal-gce-ilb-example-com"
   target_size                    = 1
   update_policy {
-    minimal_action = "REPLACE"
-    type           = "OPPORTUNISTIC"
+    max_unavailable_fixed = 1
+    minimal_action        = "REPLACE"
+    type                  = "OPPORTUNISTIC"
   }
   version {
     instance_template = google_compute_instance_template.master-us-test1-a-minimal-gce-ilb-example-com.self_link
@@ -456,8 +457,9 @@ resource "google_compute_instance_group_manager" "a-nodes-minimal-gce-ilb-exampl
   name                           = "a-nodes-minimal-gce-ilb-example-com"
   target_size                    = 1
   update_policy {
-    minimal_action = "REPLACE"
-    type           = "OPPORTUNISTIC"
+    max_unavailable_fixed = 1
+    minimal_action        = "REPLACE"
+    type                  = "OPPORTUNISTIC"
   }
   version {
     instance_template = google_compute_instance_template.nodes-minimal-gce-ilb-example-com.self_link
@@ -474,8 +476,9 @@ resource "google_compute_instance_group_manager" "b-nodes-minimal-gce-ilb-exampl
   name                           = "b-nodes-minimal-gce-ilb-example-com"
   target_size                    = 1
   update_policy {
-    minimal_action = "REPLACE"
-    type           = "OPPORTUNISTIC"
+    max_unavailable_fixed = 1
+    minimal_action        = "REPLACE"
+    type                  = "OPPORTUNISTIC"
   }
   version {
     instance_template = google_compute_instance_template.nodes-minimal-gce-ilb-example-com.self_link
diff --git a/tests/integration/update_cluster/minimal_gce_ilb_longclustername/kubernetes.tf b/tests/integration/update_cluster/minimal_gce_ilb_longclustername/kubernetes.tf
index 3df6d301d550e..637c4fc9ccb06 100644
--- a/tests/integration/update_cluster/minimal_gce_ilb_longclustername/kubernetes.tf
+++ b/tests/integration/update_cluster/minimal_gce_ilb_longclustername/kubernetes.tf
@@ -438,8 +438,9 @@ resource "google_compute_instance_group_manager" "a-master-us-test1-a-minimal-gc
   name                           = "a-master-us-test1-a-minimal-gce-with-a-very-very-very-ve-j0fh8f"
   target_size                    = 1
   update_policy {
-    minimal_action = "REPLACE"
-    type           = "OPPORTUNISTIC"
+    max_unavailable_fixed = 1
+    minimal_action        = "REPLACE"
+    type                  = "OPPORTUNISTIC"
   }
   version {
     instance_template = google_compute_instance_template.master-us-test1-a-minimal-gce-with-a-very-very-very-very-very-long-name-example-com.self_link
@@ -456,8 +457,9 @@ resource "google_compute_instance_group_manager" "a-nodes-minimal-gce-with-a-ver
   name                           = "a-nodes-minimal-gce-with-a-very-very-very-very-very-long-qk78uj"
   target_size                    = 1
   update_policy {
-    minimal_action = "REPLACE"
-    type           = "OPPORTUNISTIC"
+    max_unavailable_fixed = 1
+    minimal_action        = "REPLACE"
+    type                  = "OPPORTUNISTIC"
   }
   version {
     instance_template = google_compute_instance_template.nodes-minimal-gce-with-a-very-very-very-very-very-long-name-example-com.self_link
@@ -474,8 +476,9 @@ resource "google_compute_instance_group_manager" "b-nodes-minimal-gce-with-a-ver
   name                           = "b-nodes-minimal-gce-with-a-very-very-very-very-very-long-h6o2lg"
   target_size                    = 1
   update_policy {
-    minimal_action = "REPLACE"
-    type           = "OPPORTUNISTIC"
+    max_unavailable_fixed = 1
+    minimal_action        = "REPLACE"
+    type                  = "OPPORTUNISTIC"
   }
   version {
     instance_template = google_compute_instance_template.nodes-minimal-gce-with-a-very-very-very-very-very-long-name-example-com.self_link
diff --git a/tests/integration/update_cluster/minimal_gce_longclustername/kubernetes.tf b/tests/integration/update_cluster/minimal_gce_longclustername/kubernetes.tf
index a6e573eba4761..bac977d976d9d 100644
--- a/tests/integration/update_cluster/minimal_gce_longclustername/kubernetes.tf
+++ b/tests/integration/update_cluster/minimal_gce_longclustername/kubernetes.tf
@@ -405,8 +405,9 @@ resource "google_compute_instance_group_manager" "a-master-us-test1-a-minimal-gc
   name                           = "a-master-us-test1-a-minimal-gce-with-a-very-very-very-ve-j0fh8f"
   target_size                    = 1
   update_policy {
-    minimal_action = "REPLACE"
-    type           = "OPPORTUNISTIC"
+    max_unavailable_fixed = 1
+    minimal_action        = "REPLACE"
+    type                  = "OPPORTUNISTIC"
   }
   version {
     instance_template = google_compute_instance_template.master-us-test1-a-minimal-gce-with-a-very-very-very-very-very-long-name-example-com.self_link
@@ -423,8 +424,9 @@ resource "google_compute_instance_group_manager" "a-nodes-minimal-gce-with-a-ver
   name                           = "a-nodes-minimal-gce-with-a-very-very-very-very-very-long-qk78uj"
   target_size                    = 1
   update_policy {
-    minimal_action = "REPLACE"
-    type           = "OPPORTUNISTIC"
+    max_unavailable_fixed = 1
+    minimal_action        = "REPLACE"
+    type                  = "OPPORTUNISTIC"
   }
   version {
     instance_template = google_compute_instance_template.nodes-minimal-gce-with-a-very-very-very-very-very-long-name-example-com.self_link
@@ -441,8 +443,9 @@ resource "google_compute_instance_group_manager" "b-nodes-minimal-gce-with-a-ver
   name                           = "b-nodes-minimal-gce-with-a-very-very-very-very-very-long-h6o2lg"
   target_size                    = 1
   update_policy {
-    minimal_action = "REPLACE"
-    type           = "OPPORTUNISTIC"
+    max_unavailable_fixed = 1
+    minimal_action        = "REPLACE"
+    type                  = "OPPORTUNISTIC"
   }
   version {
     instance_template = google_compute_instance_template.nodes-minimal-gce-with-a-very-very-very-very-very-long-name-example-com.self_link
diff --git a/tests/integration/update_cluster/minimal_gce_plb/kubernetes.tf b/tests/integration/update_cluster/minimal_gce_plb/kubernetes.tf
index a97a5c952e9a0..f8e12dc9be91f 100644
--- a/tests/integration/update_cluster/minimal_gce_plb/kubernetes.tf
+++ b/tests/integration/update_cluster/minimal_gce_plb/kubernetes.tf
@@ -462,8 +462,9 @@ resource "google_compute_instance_group_manager" "a-master-us-test1-a-minimal-gc
   target_pools                   = [google_compute_target_pool.api-minimal-gce-plb-example-com.self_link]
   target_size                    = 1
   update_policy {
-    minimal_action = "REPLACE"
-    type           = "OPPORTUNISTIC"
+    max_unavailable_fixed = 1
+    minimal_action        = "REPLACE"
+    type                  = "OPPORTUNISTIC"
   }
   version {
     instance_template = google_compute_instance_template.master-us-test1-a-minimal-gce-plb-example-com.self_link
@@ -480,8 +481,9 @@ resource "google_compute_instance_group_manager" "a-nodes-minimal-gce-plb-exampl
   name                           = "a-nodes-minimal-gce-plb-example-com"
   target_size                    = 1
   update_policy {
-    minimal_action = "REPLACE"
-    type           = "OPPORTUNISTIC"
+    max_unavailable_fixed = 1
+    minimal_action        = "REPLACE"
+    type                  = "OPPORTUNISTIC"
   }
   version {
     instance_template = google_compute_instance_template.nodes-minimal-gce-plb-example-com.self_link
@@ -498,8 +500,9 @@ resource "google_compute_instance_group_manager" "b-nodes-minimal-gce-plb-exampl
   name                           = "b-nodes-minimal-gce-plb-example-com"
   target_size                    = 1
   update_policy {
-    minimal_action = "REPLACE"
-    type           = "OPPORTUNISTIC"
+    max_unavailable_fixed = 1
+    minimal_action        = "REPLACE"
+    type                  = "OPPORTUNISTIC"
   }
   version {
     instance_template = google_compute_instance_template.nodes-minimal-gce-plb-example-com.self_link
diff --git a/tests/integration/update_cluster/minimal_gce_private/kubernetes.tf b/tests/integration/update_cluster/minimal_gce_private/kubernetes.tf
index f1587836715a2..d51a0d8273662 100644
--- a/tests/integration/update_cluster/minimal_gce_private/kubernetes.tf
+++ b/tests/integration/update_cluster/minimal_gce_private/kubernetes.tf
@@ -405,8 +405,9 @@ resource "google_compute_instance_group_manager" "a-master-us-test1-a-minimal-gc
   name                           = "a-master-us-test1-a-minimal-gce-private-example-com"
   target_size                    = 1
   update_policy {
-    minimal_action = "REPLACE"
-    type           = "OPPORTUNISTIC"
+    max_unavailable_fixed = 1
+    minimal_action        = "REPLACE"
+    type                  = "OPPORTUNISTIC"
   }
   version {
     instance_template = google_compute_instance_template.master-us-test1-a-minimal-gce-private-example-com.self_link
@@ -423,8 +424,9 @@ resource "google_compute_instance_group_manager" "a-nodes-minimal-gce-private-ex
   name                           = "a-nodes-minimal-gce-private-example-com"
   target_size                    = 1
   update_policy {
-    minimal_action = "REPLACE"
-    type           = "OPPORTUNISTIC"
+    max_unavailable_fixed = 1
+    minimal_action        = "REPLACE"
+    type                  = "OPPORTUNISTIC"
   }
   version {
     instance_template = google_compute_instance_template.nodes-minimal-gce-private-example-com.self_link
@@ -441,8 +443,9 @@ resource "google_compute_instance_group_manager" "b-nodes-minimal-gce-private-ex
   name                           = "b-nodes-minimal-gce-private-example-com"
   target_size                    = 1
   update_policy {
-    minimal_action = "REPLACE"
-    type           = "OPPORTUNISTIC"
+    max_unavailable_fixed = 1
+    minimal_action        = "REPLACE"
+    type                  = "OPPORTUNISTIC"
   }
   version {
     instance_template = google_compute_instance_template.nodes-minimal-gce-private-example-com.self_link
diff --git a/upup/pkg/fi/cloudup/gcetasks/instancegroupmanager.go b/upup/pkg/fi/cloudup/gcetasks/instancegroupmanager.go
index 4fcef2a49a0e3..58e65669ad374 100644
--- a/upup/pkg/fi/cloudup/gcetasks/instancegroupmanager.go
+++ b/upup/pkg/fi/cloudup/gcetasks/instancegroupmanager.go
@@ -199,9 +199,9 @@ type terraformInstanceGroupManager struct {
 }
 
 type terraformUpdatePolicy struct {
-	MinimalAction string `cty:"minimal_action"`
-	MaxUnavailableFixed int `cty:"max_unavailable_fixed"`
-	Type          string `cty:"type"`
+	MinimalAction       string `cty:"minimal_action"`
+	MaxUnavailableFixed int    `cty:"max_unavailable_fixed"`
+	Type                string `cty:"type"`
 }
 
 type terraformVersion struct {
@@ -221,9 +221,9 @@ func (_ *InstanceGroupManager) RenderTerraform(t *terraform.TerraformTarget, a,
 	}
 	if policy := e.UpdatePolicy; policy != nil {
 		tf.UpdatePolicy = &terraformUpdatePolicy{
-			MinimalAction: policy.MinimalAction,
+			MinimalAction:       policy.MinimalAction,
 			MaxUnavailableFixed: 1,
-			Type:          policy.Type,
+			Type:                policy.Type,
 		}
 	}
 	tf.Version = &terraformVersion{