diff --git a/chart/kube-flannel/templates/config.yaml b/chart/kube-flannel/templates/config.yaml
index e147c9ddb..8736e0ac6 100644
--- a/chart/kube-flannel/templates/config.yaml
+++ b/chart/kube-flannel/templates/config.yaml
@@ -67,7 +67,7 @@ data:
         "ListenPortV6": {{ .Values.flannel.backendPortv6 }},
 {{- end }}
 {{- if .Values.flannel.psk }}
-        "PSK": {{ .Values.flannel.psk }},
+        "PSK": {{ .Values.flannel.psk | quote }},
 {{- end }}
 {{- if .Values.flannel.mtu }}
         "MTU": {{ .Values.flannel.mtu }},