diff --git a/api/payloads/manifest.go b/api/payloads/manifest.go
index 3640f9d05..e93dbce10 100644
--- a/api/payloads/manifest.go
+++ b/api/payloads/manifest.go
@@ -193,7 +193,7 @@ func (m Manifest) Validate() error {
 func (a ManifestApplication) Validate() error {
 	return validation.ValidateStruct(&a,
 		validation.Field(&a.Name, payload_validation.StrictlyRequired),
-		validation.Field(&a.DefaultRoute, validation.When(a.RandomRoute, validation.Nil.Error("and random-route may not be used together"))),
+		validation.Field(&a.DefaultRoute, validation.When(a.RandomRoute && a.DefaultRoute, validation.Nil.Error("and random-route may not be used together"))),
 		validation.Field(&a.DiskQuota, validation.By(validateAmountWithUnit), validation.When(a.AltDiskQuota != nil, validation.Nil.Error("and disk-quota may not be used together"))),
 		validation.Field(&a.AltDiskQuota, validation.By(validateAmountWithUnit)),
 		validation.Field(&a.Instances, validation.Min(0)),
diff --git a/api/payloads/manifest_test.go b/api/payloads/manifest_test.go
index 316bf8306..d028d989a 100644
--- a/api/payloads/manifest_test.go
+++ b/api/payloads/manifest_test.go
@@ -198,6 +198,17 @@ var _ = Describe("Manifest payload", func() {
 					Expect(validateErr).To(MatchError("default-route: and random-route may not be used together."))
 				})
 			})
+
+			When("only the random-route flag is set", func() {
+				BeforeEach(func() {
+					testManifest.DefaultRoute = false
+					testManifest.RandomRoute = true
+				})
+
+				It("does not return a validation error", func() {
+					Expect(validateErr).NotTo(HaveOccurred())
+				})
+			})
 		})
 	})