diff --git a/pkg/controller/vault/vault_controller.go b/pkg/controller/vault/vault_controller.go
index 5cd3077e..43957dc4 100644
--- a/pkg/controller/vault/vault_controller.go
+++ b/pkg/controller/vault/vault_controller.go
@@ -948,7 +948,7 @@ func deploymentForConfigurer(v *vaultv1alpha1.Vault, configmaps corev1.ConfigMap
 	// merge provided VaultConfigurerPodSpec into the PodSpec defined above
 	// the values in VaultConfigurerPodSpec will never overwrite fields defined in the PodSpec above
 	if v.Spec.VaultConfigurerPodSpec != nil {
-		if err := mergo.Merge(&podSpec, corev1.PodSpec(*v.Spec.VaultConfigurerPodSpec)); err != nil {
+		if err := mergo.Merge(&podSpec, corev1.PodSpec(*v.Spec.VaultConfigurerPodSpec), mergo.WithAppendSlice); err != nil {
 			return nil, err
 		}
 	}