diff --git a/openapi/bundled-api-external-b2b-pa-v1.yaml b/openapi/bundled-api-external-b2b-pa-v1.yaml
index 58c18a0f..be698112 100644
--- a/openapi/bundled-api-external-b2b-pa-v1.yaml
+++ b/openapi/bundled-api-external-b2b-pa-v1.yaml
@@ -1647,7 +1647,7 @@ components:
               utilizzabili in un nome file.
           docIdx:
             maxLength: 3
-            pattern: ^\d+$
+            pattern: ^\\d+$
             type: string
             description: Indice del documento partendo da 0.
     NotificationFeePolicy:
diff --git a/openapi/how-to-generate-the-bundled-openapi-definition.md b/openapi/how-to-generate-the-bundled-openapi-definition.md
index 9da57682..9e6eb3e9 100644
--- a/openapi/how-to-generate-the-bundled-openapi-definition.md
+++ b/openapi/how-to-generate-the-bundled-openapi-definition.md
@@ -24,7 +24,8 @@
 ```
 6. Replace the reference of errors from `#/components/schemas/schemas-ProblemError` to `#/components/schemas/ProblemError`
 7. Remove `schemas-ProblemError`.
-8. Done
+8. On `NotificationDocument.docIdx` replace `pattern: ^\d+$` with `pattern: ^\\d+$` due to [string pattern definition bug](https://github.com/pagopa/openapi-codegen-ts/tree/v13.0.1#about-string-pattern-definition).
+9. Done
 
 ```
 # Run the following command form ./openapi
diff --git a/package-lock.json b/package-lock.json
index 1901ed75..2f0fa403 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -21,7 +21,7 @@
       },
       "devDependencies": {
         "@pagopa/eslint-config": "^3.0.0",
-        "@pagopa/openapi-codegen-ts": "^12.1.2",
+        "@pagopa/openapi-codegen-ts": "^13.0.1",
         "@types/express": "^4.17.15",
         "@types/jest": "^29.2.6",
         "@types/node": "^18.11.18",
@@ -1257,12 +1257,12 @@
       }
     },
     "node_modules/@pagopa/openapi-codegen-ts": {
-      "version": "12.1.2",
-      "resolved": "https://registry.npmjs.org/@pagopa/openapi-codegen-ts/-/openapi-codegen-ts-12.1.2.tgz",
-      "integrity": "sha512-pJS4WTS4XkV6fyNFRfL9J/8CBcV+VUHWnweLNYwEgRXvYuaday/aaEEy/7JRjKuMI0c0jfX0gq8SbspMb/lx0A==",
+      "version": "13.0.1",
+      "resolved": "https://registry.npmjs.org/@pagopa/openapi-codegen-ts/-/openapi-codegen-ts-13.0.1.tgz",
+      "integrity": "sha512-kJ/EWR4XkwRxz/yk5cPra6JTCnKx75YvlkJxKbw61XvrfJwrKykJzyr5lgMQFLc5te/gXLyl2cMh7BI3ncaT8Q==",
       "dev": true,
       "dependencies": {
-        "@pagopa/ts-commons": "^10.3.0",
+        "@pagopa/ts-commons": "^10.15.0",
         "fs-extra": "^6.0.0",
         "nunjucks": "^3.2.3",
         "openapi-types": "^10.0.0",
@@ -1291,9 +1291,9 @@
       }
     },
     "node_modules/@pagopa/ts-commons": {
-      "version": "10.13.0",
-      "resolved": "https://registry.npmjs.org/@pagopa/ts-commons/-/ts-commons-10.13.0.tgz",
-      "integrity": "sha512-NE1RXpi5R7DlG9HdXCZZYj7DLodPMTEsusdDmCjJBlvsHRLlRsvGUx2mgA4oh+iFA+nGE9mDIbBoTN9lwGjqfQ==",
+      "version": "10.15.0",
+      "resolved": "https://registry.npmjs.org/@pagopa/ts-commons/-/ts-commons-10.15.0.tgz",
+      "integrity": "sha512-MTmD0geIN9L9vnEYjPTE7v6Bu+IRTFMre+3K4LWYjy1AaRmYcpSrc9HTZgyCRW8uLCvw1BmDKcKtSiETM817kw==",
       "dependencies": {
         "abort-controller": "^3.0.0",
         "agentkeepalive": "^4.1.4",
@@ -8296,12 +8296,12 @@
       }
     },
     "@pagopa/openapi-codegen-ts": {
-      "version": "12.1.2",
-      "resolved": "https://registry.npmjs.org/@pagopa/openapi-codegen-ts/-/openapi-codegen-ts-12.1.2.tgz",
-      "integrity": "sha512-pJS4WTS4XkV6fyNFRfL9J/8CBcV+VUHWnweLNYwEgRXvYuaday/aaEEy/7JRjKuMI0c0jfX0gq8SbspMb/lx0A==",
+      "version": "13.0.1",
+      "resolved": "https://registry.npmjs.org/@pagopa/openapi-codegen-ts/-/openapi-codegen-ts-13.0.1.tgz",
+      "integrity": "sha512-kJ/EWR4XkwRxz/yk5cPra6JTCnKx75YvlkJxKbw61XvrfJwrKykJzyr5lgMQFLc5te/gXLyl2cMh7BI3ncaT8Q==",
       "dev": true,
       "requires": {
-        "@pagopa/ts-commons": "^10.3.0",
+        "@pagopa/ts-commons": "^10.15.0",
         "fs-extra": "^6.0.0",
         "nunjucks": "^3.2.3",
         "openapi-types": "^10.0.0",
@@ -8321,9 +8321,9 @@
       }
     },
     "@pagopa/ts-commons": {
-      "version": "10.13.0",
-      "resolved": "https://registry.npmjs.org/@pagopa/ts-commons/-/ts-commons-10.13.0.tgz",
-      "integrity": "sha512-NE1RXpi5R7DlG9HdXCZZYj7DLodPMTEsusdDmCjJBlvsHRLlRsvGUx2mgA4oh+iFA+nGE9mDIbBoTN9lwGjqfQ==",
+      "version": "10.15.0",
+      "resolved": "https://registry.npmjs.org/@pagopa/ts-commons/-/ts-commons-10.15.0.tgz",
+      "integrity": "sha512-MTmD0geIN9L9vnEYjPTE7v6Bu+IRTFMre+3K4LWYjy1AaRmYcpSrc9HTZgyCRW8uLCvw1BmDKcKtSiETM817kw==",
       "requires": {
         "abort-controller": "^3.0.0",
         "agentkeepalive": "^4.1.4",
diff --git a/package.json b/package.json
index 651cbd89..c938b0b4 100644
--- a/package.json
+++ b/package.json
@@ -23,7 +23,7 @@
   "license": "SEE LICENSE IN LICENSE",
   "devDependencies": {
     "@pagopa/eslint-config": "^3.0.0",
-    "@pagopa/openapi-codegen-ts": "^12.1.2",
+    "@pagopa/openapi-codegen-ts": "^13.0.1",
     "@types/express": "^4.17.15",
     "@types/jest": "^29.2.6",
     "@types/node": "^18.11.18",