diff --git a/charts/longhorn/templates/registry-secret.yaml b/charts/longhorn/templates/registry-secret.yaml
index 3c6b1dc..1eaaac4 100644
--- a/charts/longhorn/templates/registry-secret.yaml
+++ b/charts/longhorn/templates/registry-secret.yaml
@@ -1,5 +1,8 @@
 {{- if .Values.privateRegistry.createSecret }}
 {{- if .Values.privateRegistry.registrySecret }}
+{{- if not (kindIs "string" .Values.privateRegistry.registrySecret) }}
+{{- fail "The privateRegistry.registrySecret value must be a string" }}
+{{- end }}
 apiVersion: v1
 kind: Secret
 metadata:
@@ -10,4 +13,4 @@
 data:
   .dockerconfigjson: {{ template "secret" . }}
 {{- end }}
-{{- end }}
\ No newline at end of file
+{{- end }}