diff --git a/pkg/controller/webhooks/postgresql.go b/pkg/controller/webhooks/postgresql.go
index a2eb98849..f00a9ec28 100644
--- a/pkg/controller/webhooks/postgresql.go
+++ b/pkg/controller/webhooks/postgresql.go
@@ -101,15 +101,14 @@ func (p *PostgreSQLWebhookHandler) validatePostgreSQL(ctx context.Context, newOb
 		}
 
 		// Validate major upgrades
-		allErrs = append(allErrs, validateMajorVersionUpgrade(newPg, oldPg))
+		if err := validateMajorVersionUpgrade(newPg, oldPg); err != nil {
+			allErrs = append(allErrs, err)
+		}
 	}
 
 	// Validate Vacuum and Repack settings
 	if err := validateVacuumRepack(newPg.Spec.Parameters.Service.VacuumEnabled, newPg.Spec.Parameters.Service.RepackEnabled); err != nil {
-		allErrs = append(allErrs, field.Forbidden(
-			field.NewPath("spec.parameters.service"),
-			fmt.Sprintf("pg.Spec.Parameters.Service.VacuumEnabled and pg.Spec.Parameters.Service.RepackEnabled settings can't be both disabled: %s", err.Error()),
-		))
+		allErrs = append(allErrs, err)
 	}
 
 	// Validate quotas if enabled
@@ -244,9 +243,12 @@ func (p *PostgreSQLWebhookHandler) checkGuaranteedAvailability(pg *vshnv1.VSHNPo
 	return allErrs
 }
 
-func validateVacuumRepack(vacuum, repack bool) error {
+func validateVacuumRepack(vacuum, repack bool) *field.Error {
 	if !vacuum && !repack {
-		return fmt.Errorf("repack cannot be enabled without vacuum")
+		return field.Forbidden(
+			field.NewPath("spec.parameters.service"),
+			"pg.Spec.Parameters.Service.VacuumEnabled and pg.Spec.Parameters.Service.RepackEnabled settings can't be both disabled",
+		)
 	}
 	return nil
 }
diff --git a/pkg/controller/webhooks/postgresql_test.go b/pkg/controller/webhooks/postgresql_test.go
index 5602a3f3a..999ffbeb2 100644
--- a/pkg/controller/webhooks/postgresql_test.go
+++ b/pkg/controller/webhooks/postgresql_test.go
@@ -2,6 +2,7 @@ package webhooks
 
 import (
 	"context"
+	"k8s.io/apimachinery/pkg/util/validation/field"
 	"testing"
 
 	"github.com/go-logr/logr"
@@ -492,3 +493,113 @@ func TestPostgreSQLWebhookHandler_ValidateDelete(t *testing.T) {
 	assert.NoError(t, err)
 
 }
+
+func TestPostgreSQLWebhookHandler_ValidateMajorVersionUpgrade(t *testing.T) {
+	tests := []struct {
+		name      string
+		new       *vshnv1.VSHNPostgreSQL
+		old       *vshnv1.VSHNPostgreSQL
+		expectErr *field.Error
+	}{
+		{
+			name: "GivenSameMajorVersion_ThenNoError",
+			new: &vshnv1.VSHNPostgreSQL{
+				Spec: vshnv1.VSHNPostgreSQLSpec{
+					Parameters: vshnv1.VSHNPostgreSQLParameters{
+						Service: vshnv1.VSHNPostgreSQLServiceSpec{
+							MajorVersion: "15",
+						},
+					},
+				},
+			},
+			old: &vshnv1.VSHNPostgreSQL{
+				Spec: vshnv1.VSHNPostgreSQLSpec{
+					Parameters: vshnv1.VSHNPostgreSQLParameters{
+						Service: vshnv1.VSHNPostgreSQLServiceSpec{
+							MajorVersion: "15",
+						},
+					},
+				},
+			},
+			expectErr: nil,
+		},
+		{
+			name: "GivenOneMajorVersionUpdate_ThenNoError",
+			new: &vshnv1.VSHNPostgreSQL{
+				Spec: vshnv1.VSHNPostgreSQLSpec{
+					Parameters: vshnv1.VSHNPostgreSQLParameters{
+						Service: vshnv1.VSHNPostgreSQLServiceSpec{
+							MajorVersion: "16",
+						},
+					},
+				},
+			},
+			old: &vshnv1.VSHNPostgreSQL{
+				Spec: vshnv1.VSHNPostgreSQLSpec{
+					Parameters: vshnv1.VSHNPostgreSQLParameters{
+						Service: vshnv1.VSHNPostgreSQLServiceSpec{
+							MajorVersion: "15",
+						},
+					},
+				},
+			},
+			expectErr: nil,
+		},
+		{
+			name: "GivenTwoMajorVersionsUpdate_ThenError",
+			new: &vshnv1.VSHNPostgreSQL{
+				Spec: vshnv1.VSHNPostgreSQLSpec{
+					Parameters: vshnv1.VSHNPostgreSQLParameters{
+						Service: vshnv1.VSHNPostgreSQLServiceSpec{
+							MajorVersion: "17",
+						},
+					},
+				},
+			},
+			old: &vshnv1.VSHNPostgreSQL{
+				Spec: vshnv1.VSHNPostgreSQLSpec{
+					Parameters: vshnv1.VSHNPostgreSQLParameters{
+						Service: vshnv1.VSHNPostgreSQLServiceSpec{
+							MajorVersion: "15",
+						},
+					},
+				},
+			},
+			expectErr: field.Forbidden(
+				field.NewPath("spec.parameters.service.majorVersion"),
+				"only one major version upgrade at a time is allowed",
+			),
+		},
+		{
+			name: "GivenOneMajorVersionsBehind_ThenError",
+			new: &vshnv1.VSHNPostgreSQL{
+				Spec: vshnv1.VSHNPostgreSQLSpec{
+					Parameters: vshnv1.VSHNPostgreSQLParameters{
+						Service: vshnv1.VSHNPostgreSQLServiceSpec{
+							MajorVersion: "14",
+						},
+					},
+				},
+			},
+			old: &vshnv1.VSHNPostgreSQL{
+				Spec: vshnv1.VSHNPostgreSQLSpec{
+					Parameters: vshnv1.VSHNPostgreSQLParameters{
+						Service: vshnv1.VSHNPostgreSQLServiceSpec{
+							MajorVersion: "15",
+						},
+					},
+				},
+			},
+			expectErr: field.Forbidden(
+				field.NewPath("spec.parameters.service.majorVersion"),
+				"only one major version upgrade at a time is allowed",
+			),
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			err := validateMajorVersionUpgrade(tt.new, tt.old)
+			assert.Equal(t, tt.expectErr, err)
+		})
+	}
+}