diff --git a/api/v1/inferencepool_types.go b/api/v1/inferencepool_types.go
index ed8e0e1f0..7f76b03d8 100644
--- a/api/v1/inferencepool_types.go
+++ b/api/v1/inferencepool_types.go
@@ -123,7 +123,8 @@ type Extension struct {
 	// Service.
 	//
 	// +optional
-	PortNumber PortNumber `json:"portNumber,omitempty"`
+	//nolint:kubeapilinter // ignore kubeapilinter here as we want to use pointer here as 0 usually means all ports.
+	PortNumber *PortNumber `json:"portNumber,omitempty"`
 
 	// Configures how the gateway handles the case when the extension is not responsive.
 	// Defaults to failClose.
diff --git a/api/v1/zz_generated.deepcopy.go b/api/v1/zz_generated.deepcopy.go
index 0cdf1700a..1e20396d3 100644
--- a/api/v1/zz_generated.deepcopy.go
+++ b/api/v1/zz_generated.deepcopy.go
@@ -33,6 +33,11 @@ func (in *Extension) DeepCopyInto(out *Extension) {
 		*out = new(Group)
 		**out = **in
 	}
+	if in.PortNumber != nil {
+		in, out := &in.PortNumber, &out.PortNumber
+		*out = new(PortNumber)
+		**out = **in
+	}
 }
 
 // DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new Extension.
diff --git a/apix/v1alpha2/inferencepool_conversion_test.go b/apix/v1alpha2/inferencepool_conversion_test.go
index 847372b53..8da8c0f4d 100644
--- a/apix/v1alpha2/inferencepool_conversion_test.go
+++ b/apix/v1alpha2/inferencepool_conversion_test.go
@@ -104,7 +104,7 @@ func TestInferencePoolConvertTo(t *testing.T) {
 						Group:       &v1Group,
 						Kind:        v1Kind,
 						Name:        "my-epp-service",
-						PortNumber:  v1PortNumber,
+						PortNumber:  &v1PortNumber,
 						FailureMode: v1FailureMode,
 					},
 				},
@@ -239,7 +239,7 @@ func TestInferencePoolConvertFrom(t *testing.T) {
 						Group:       &v1Group,
 						Kind:        v1Kind,
 						Name:        "my-epp-service",
-						PortNumber:  v1PortNumber,
+						PortNumber:  &v1PortNumber,
 						FailureMode: v1FailureMode,
 					},
 				},