Pin version

Author: felixfbecker

package.json

@@ -47,7 +47,7 @@
     "rollup": "1.27.8",
     "rollup-plugin-terser": "5.1.2",
     "rollup-plugin-typescript2": "0.25.3",
-    "typescript": "^3.8.3"
+    "typescript": "3.8.3"
   },
   "dependencies": {}
 }