diff --git a/conformance/tests/gateway-observed-generation-bump.go b/conformance/tests/gateway-observed-generation-bump.go
index d7b5d87bda..12f46d2358 100644
--- a/conformance/tests/gateway-observed-generation-bump.go
+++ b/conformance/tests/gateway-observed-generation-bump.go
@@ -23,6 +23,7 @@ import (
 
 	"github.com/stretchr/testify/require"
 	"k8s.io/apimachinery/pkg/types"
+	"sigs.k8s.io/controller-runtime/pkg/client"
 
 	"sigs.k8s.io/gateway-api/apis/v1beta1"
 	"sigs.k8s.io/gateway-api/conformance/utils/kubernetes"
@@ -69,8 +70,8 @@ var GatewayObservedGenerationBump = suite.ConformanceTest{
 				},
 			})
 
-			err = s.Client.Update(ctx, mutate)
-			require.NoErrorf(t, err, "error updating the Gateway: %v", err)
+			err = s.Client.Patch(ctx, mutate, client.MergeFrom(original))
+			require.NoErrorf(t, err, "error patching the Gateway: %v", err)
 
 			// Ensure the generation and observedGeneration sync up
 			kubernetes.NamespacesMustBeAccepted(t, s.Client, s.TimeoutConfig, namespaces)
diff --git a/conformance/tests/gatewayclass-observed-generation-bump.go b/conformance/tests/gatewayclass-observed-generation-bump.go
index 0a699ff514..e1e556b590 100644
--- a/conformance/tests/gatewayclass-observed-generation-bump.go
+++ b/conformance/tests/gatewayclass-observed-generation-bump.go
@@ -23,6 +23,7 @@ import (
 
 	"github.com/stretchr/testify/require"
 	"k8s.io/apimachinery/pkg/types"
+	"sigs.k8s.io/controller-runtime/pkg/client"
 
 	"sigs.k8s.io/gateway-api/apis/v1beta1"
 	"sigs.k8s.io/gateway-api/conformance/utils/kubernetes"
@@ -58,8 +59,8 @@ var GatewayClassObservedGenerationBump = suite.ConformanceTest{
 			desc := "new"
 			mutate.Spec.Description = &desc
 
-			err = s.Client.Update(ctx, mutate)
-			require.NoErrorf(t, err, "error updating the GatewayClass: %v", err)
+			err = s.Client.Patch(ctx, mutate, client.MergeFrom(original))
+			require.NoErrorf(t, err, "error patching the GatewayClass: %v", err)
 
 			// Ensure the generation and observedGeneration sync up
 			kubernetes.GWCMustHaveAcceptedConditionAny(t, s.Client, s.TimeoutConfig, gwc.Name)
diff --git a/conformance/tests/httproute-observed-generation-bump.go b/conformance/tests/httproute-observed-generation-bump.go
index 590dcc6fed..c7571856bc 100644
--- a/conformance/tests/httproute-observed-generation-bump.go
+++ b/conformance/tests/httproute-observed-generation-bump.go
@@ -24,6 +24,7 @@ import (
 	"github.com/stretchr/testify/require"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/types"
+	"sigs.k8s.io/controller-runtime/pkg/client"
 
 	"sigs.k8s.io/gateway-api/apis/v1beta1"
 	"sigs.k8s.io/gateway-api/conformance/utils/kubernetes"
@@ -65,8 +66,8 @@ var HTTPRouteObservedGenerationBump = suite.ConformanceTest{
 
 			mutate := original.DeepCopy()
 			mutate.Spec.Rules[0].BackendRefs[0].Name = "infra-backend-v2"
-			err = s.Client.Update(ctx, mutate)
-			require.NoErrorf(t, err, "error updating the HTTPRoute: %v", err)
+			err = s.Client.Patch(ctx, mutate, client.MergeFrom(original))
+			require.NoErrorf(t, err, "error patching the HTTPRoute: %v", err)
 
 			kubernetes.HTTPRouteMustHaveCondition(t, s.Client, s.TimeoutConfig, routeNN, gwNN, acceptedCondition)