diff --git a/gts/README.md b/gts/README.md
index 1520e22..739fb10 100644
--- a/gts/README.md
+++ b/gts/README.md
@@ -2,7 +2,7 @@
 
 Python helpers and a reference HTTP service for the [Global Type System (GTS)](https://github.com/globaltypesystem/gts-spec). The package supports GTS identifier parsing, JSON Schema-backed validation, schema compatibility and derivation checks, traits, casting, queries, file loading, a CLI, and a FastAPI application.
 
-The package targets GTS specification v0.13.1 and requires Python 3.9 or later.
+The package targets GTS specification v0.13.4 and requires Python 3.9 or later.
 
 ## Installation
 
diff --git a/gts/openapi.json b/gts/openapi.json
index 69dc264..3e9b962 100644
--- a/gts/openapi.json
+++ b/gts/openapi.json
@@ -2,7 +2,7 @@
   "openapi": "3.1.0",
   "info": {
     "title": "GTS Server",
-    "version": "0.13.1"
+    "version": "0.13.4"
   },
   "paths": {
     "/entities": {
diff --git a/gts/pyproject.toml b/gts/pyproject.toml
index da05785..2405c35 100644
--- a/gts/pyproject.toml
+++ b/gts/pyproject.toml
@@ -4,7 +4,7 @@ build-backend = "hatchling.build"
 
 [project]
 name = "gts"
-version = "0.13.2"
+version = "0.13.4"
 description = "Global Type System (GTS) helpers: identifiers, parsing, validation, and operations"
 readme = "README.md"
 authors = [{ name = "GTS Community" }]
diff --git a/gts/src/gts/_server.py b/gts/src/gts/_server.py
index e7559fc..f5135ae 100644
--- a/gts/src/gts/_server.py
+++ b/gts/src/gts/_server.py
@@ -188,7 +188,7 @@ def __init__(
         self.host = host
         self.port = port
         self.base_url = f"http://{self.host}:{self.port}"
-        self.app = FastAPI(title="GTS Server", version="0.13.1")
+        self.app = FastAPI(title="GTS Server", version="0.13.4")
         self.app.add_middleware(
             _RequestLoggingMiddleware,
             verbose=self.ops.verbose,