diff --git a/charts/matrix-stack/templates/matrix-authentication-service/_helpers.tpl b/charts/matrix-stack/templates/matrix-authentication-service/_helpers.tpl
index 0a61690e3..be62fc2f2 100644
--- a/charts/matrix-stack/templates/matrix-authentication-service/_helpers.tpl
+++ b/charts/matrix-stack/templates/matrix-authentication-service/_helpers.tpl
@@ -283,7 +283,7 @@ config.yaml: |
               "nameSuffix" "matrix-authentication-service"
               "containerName" (.containerName | default "render-config")
               "templatesVolume" (.templatesVolume | default "plain-config")
-              "overrides" (list "config.yaml")
+              "underrides" (list "config.yaml")
               "outputFile" "config.yaml"
               "resources" .resources
               "containersSecurityContext" .containersSecurityContext