diff --git a/specification/_types/analysis/icu-plugin.ts b/specification/_types/analysis/icu-plugin.ts
index 136b27550c..22b36ad275 100644
--- a/specification/_types/analysis/icu-plugin.ts
+++ b/specification/_types/analysis/icu-plugin.ts
@@ -41,6 +41,7 @@ export class IcuNormalizationCharFilter extends CharFilterBase {
   type: 'icu_normalizer'
   mode?: IcuNormalizationMode
   name?: IcuNormalizationType
+  unicode_set_filter?: string
 }
 
 export class IcuFoldingTokenFilter extends TokenFilterBase {