diff --git a/.changeset/fix-tslib-missing-dependency.md b/.changeset/fix-tslib-missing-dependency.md
new file mode 100644
index 00000000..3d78f078
--- /dev/null
+++ b/.changeset/fix-tslib-missing-dependency.md
@@ -0,0 +1,5 @@
+---
+"changesets-gitlab": patch
+---
+
+Add `tslib` to `dependencies`. The compiled output imports `tslib` at runtime (via the `importHelpers` tsconfig option), but it was missing from `package.json`, causing `ERR_MODULE_NOT_FOUND: Cannot find package 'tslib'` when running via `npx`.
diff --git a/package.json b/package.json
index 65113695..52b84ca5 100644
--- a/package.json
+++ b/package.json
@@ -69,6 +69,7 @@
     "micromatch": "^4.0.8",
     "p-limit": "^7.3.2",
     "semver": "^7.8.5",
+    "tslib": "^2.8.1",
     "yaml": "^2.9.1"
   },
   "devDependencies": {
diff --git a/yarn.lock b/yarn.lock
index 66a8468c..4749c02d 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -5373,6 +5373,7 @@ __metadata:
     simple-git-hooks: "npm:^2.14.0"
     size-limit: "npm:^14.0.0"
     size-limit-preset-node-lib: "npm:^0.4.0"
+    tslib: "npm:^2.8.1"
     tsx: "npm:^4.23.13"
     type-coverage: "npm:^2.30.1"
     typescript: "npm:@typescript/typescript6@^6.0.2"