diff --git a/pkg/retention/retention_policy.go b/pkg/retention/retention_policy.go
index 1e5873cb..23cd97d8 100644
--- a/pkg/retention/retention_policy.go
+++ b/pkg/retention/retention_policy.go
@@ -5,6 +5,7 @@ type RetentionType string
 const (
 	LifecycleReleaseRetentionType  = RetentionType("LifecycleRelease")
 	LifecycleTentacleRetentionType = RetentionType("LifecycleTentacle")
+	RunbookRetentionType           = RetentionType("RunbookRetention")
 )
 
 const (
diff --git a/pkg/retention/space_default_runbook_retention_policy.go b/pkg/retention/space_default_runbook_retention_policy.go
new file mode 100644
index 00000000..d9625f42
--- /dev/null
+++ b/pkg/retention/space_default_runbook_retention_policy.go
@@ -0,0 +1,40 @@
+package retention
+
+import "github.com/OctopusDeploy/go-octopusdeploy/v2/pkg/resources"
+
+type RunbookRetentionPolicy struct {
+	QuantityToKeep int    `json:"QuantityToKeep"`
+	Strategy       string `json:"Strategy"`
+	Unit           string `json:"Unit"`
+	SpaceDefaultRetentionPolicy
+}
+
+func NewCountBasedRunbookRetentionPolicy(quantityToKeep int, unit string, spaceId string, policyId string) *RunbookRetentionPolicy {
+	return &RunbookRetentionPolicy{
+		QuantityToKeep: quantityToKeep,
+		Strategy:       RetentionStrategyCount,
+		Unit:           unit,
+		SpaceDefaultRetentionPolicy: SpaceDefaultRetentionPolicy{
+			SpaceId:       spaceId,
+			RetentionType: RunbookRetentionType,
+			Resource: resources.Resource{
+				ID: policyId,
+			},
+		},
+	}
+}
+
+func NewKeepForeverRunbookRetentionPolicy(spaceId string, policyId string) *RunbookRetentionPolicy {
+	return &RunbookRetentionPolicy{
+		QuantityToKeep: 0,
+		Strategy:       RetentionStrategyForever,
+		Unit:           RetentionUnitItems,
+		SpaceDefaultRetentionPolicy: SpaceDefaultRetentionPolicy{
+			SpaceId:       spaceId,
+			RetentionType: RunbookRetentionType,
+			Resource: resources.Resource{
+				ID: policyId,
+			},
+		},
+	}
+}
diff --git a/test/e2e/space_default_retention_policy_service_test.go b/test/e2e/space_default_retention_policy_service_test.go
index 48a25856..dcc5d62a 100644
--- a/test/e2e/space_default_retention_policy_service_test.go
+++ b/test/e2e/space_default_retention_policy_service_test.go
@@ -1,10 +1,11 @@
 package e2e
 
 import (
+	"testing"
+
 	"github.com/OctopusDeploy/go-octopusdeploy/v2/pkg/retention"
 	"github.com/OctopusDeploy/go-octopusdeploy/v2/pkg/spaces"
 	"github.com/stretchr/testify/require"
-	"testing"
 )
 
 func TestReadLifecycleReleaseRetentionDefaultPolicy(t *testing.T) {
@@ -39,6 +40,22 @@ func TestReadLifecycleTentacleRetentionDefaultPolicy(t *testing.T) {
 	require.Equal(t, res.RetentionType, retention.LifecycleTentacleRetentionType)
 }
 
+func TestReadRunbookRetentionDefaultPolicy(t *testing.T) {
+	client := getOctopusClient()
+	require.NotNil(t, client)
+
+	defaultSpace, _ := spaces.GetDefaultSpace(client)
+	query := retention.SpaceDefaultRetentionPolicyQuery{
+		RetentionType: retention.RunbookRetentionType,
+		SpaceID:       defaultSpace.ID,
+	}
+	res, err := retention.Get(client, query)
+
+	require.NoError(t, err)
+	require.NotNil(t, res)
+	require.Equal(t, res.RetentionType, retention.RunbookRetentionType)
+}
+
 func TestModifyLifecycleReleaseRetentionDefaultPolicy(t *testing.T) {
 	client := getOctopusClient()
 	require.NotNil(t, client)
@@ -83,3 +100,46 @@ func TestModifyLifecycleTentacleRetentionDefaultPolicy(t *testing.T) {
 	require.Equal(t, res.Strategy, retention.RetentionStrategyCount)
 	require.Equal(t, res.Unit, retention.RetentionUnitDays)
 }
+
+func TestModifyRunbookRetentionDefaultPolicyUsingCount(t *testing.T) {
+	client := getOctopusClient()
+	require.NotNil(t, client)
+	defaultSpace, _ := spaces.GetDefaultSpace(client)
+	query := retention.SpaceDefaultRetentionPolicyQuery{
+		RetentionType: retention.RunbookRetentionType,
+		SpaceID:       defaultSpace.ID,
+	}
+	defaultSpaceRunbookPolicy, err := retention.Get(client, query)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	policy := retention.NewCountBasedRunbookRetentionPolicy(3, retention.RetentionUnitDays, defaultSpace.ID, defaultSpaceRunbookPolicy.ID)
+	res, err := retention.Update(client, policy)
+	require.NoError(t, err)
+	require.NotNil(t, res)
+	require.Equal(t, res.QuantityToKeep, 3)
+	require.Equal(t, res.Strategy, retention.RetentionStrategyCount)
+	require.Equal(t, res.Unit, retention.RetentionUnitDays)
+}
+
+func TestModifyRunbookRetentionDefaultPolicyUsingForever(t *testing.T) {
+	client := getOctopusClient()
+	require.NotNil(t, client)
+	defaultSpace, _ := spaces.GetDefaultSpace(client)
+	query := retention.SpaceDefaultRetentionPolicyQuery{
+		RetentionType: retention.RunbookRetentionType,
+		SpaceID:       defaultSpace.ID,
+	}
+	defaultSpaceRunbookPolicy, err := retention.Get(client, query)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	policy := retention.NewKeepForeverRunbookRetentionPolicy(defaultSpace.ID, defaultSpaceRunbookPolicy.ID)
+	res, err := retention.Update(client, policy)
+	require.NoError(t, err)
+	require.NotNil(t, res)
+	require.Equal(t, res.QuantityToKeep, 0)
+	require.Equal(t, res.Strategy, retention.RetentionStrategyForever)
+}