diff --git a/package.json b/package.json
index 16da7f26..6b463343 100644
--- a/package.json
+++ b/package.json
@@ -26,7 +26,7 @@
     "jest": "28.1.3",
     "prettier": "3.6.2",
     "ts-node": "10.9.2",
-    "typescript": "4.7.4"
+    "typescript": "5.9.3"
   },
   "packageManager": "yarn@3.8.7",
   "dependencies": {
diff --git a/src/2020/Day-11-Seating-System/package.json b/src/2020/Day-11-Seating-System/package.json
index 7466e466..bd231957 100644
--- a/src/2020/Day-11-Seating-System/package.json
+++ b/src/2020/Day-11-Seating-System/package.json
@@ -10,6 +10,6 @@
   "license": "MIT",
   "devDependencies": {
     "parcel": "2.16.0",
-    "typescript": "4.7.4"
+    "typescript": "5.9.3"
   }
 }
diff --git a/yarn.lock b/yarn.lock
index 67e458b5..228dd076 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -3202,7 +3202,7 @@ __metadata:
     jest: 28.1.3
     prettier: 3.6.2
     ts-node: 10.9.2
-    typescript: 4.7.4
+    typescript: 5.9.3
   languageName: unknown
   linkType: soft
 
@@ -7210,23 +7210,23 @@ __metadata:
   languageName: node
   linkType: hard
 
-"typescript@npm:4.7.4":
-  version: 4.7.4
-  resolution: "typescript@npm:4.7.4"
+"typescript@npm:5.9.3":
+  version: 5.9.3
+  resolution: "typescript@npm:5.9.3"
   bin:
     tsc: bin/tsc
     tsserver: bin/tsserver
-  checksum: 5750181b1cd7e6482c4195825547e70f944114fb47e58e4aa7553e62f11b3f3173766aef9c281783edfd881f7b8299cf35e3ca8caebe73d8464528c907a164df
+  checksum: 0d0ffb84f2cd072c3e164c79a2e5a1a1f4f168e84cb2882ff8967b92afe1def6c2a91f6838fb58b168428f9458c57a2ba06a6737711fdd87a256bbe83e9a217f
   languageName: node
   linkType: hard
 
-"typescript@patch:typescript@4.7.4#~builtin<compat/typescript>":
-  version: 4.7.4
-  resolution: "typescript@patch:typescript@npm%3A4.7.4#~builtin<compat/typescript>::version=4.7.4&hash=65a307"
+"typescript@patch:typescript@5.9.3#~builtin<compat/typescript>":
+  version: 5.9.3
+  resolution: "typescript@patch:typescript@npm%3A5.9.3#~builtin<compat/typescript>::version=5.9.3&hash=5786d5"
   bin:
     tsc: bin/tsc
     tsserver: bin/tsserver
-  checksum: 9096d8f6c16cb80ef3bf96fcbbd055bf1c4a43bd14f3b7be45a9fbe7ada46ec977f604d5feed3263b4f2aa7d4c7477ce5f9cd87de0d6feedec69a983f3a4f93e
+  checksum: a5a6dc399d3761ded54192031f11d3ad5df8001c7febe3fbbc8098efcb552cdf8f2f402b3618c56dafcd04fef63dee005f4900f608e185404caedc46480539ed
   languageName: node
   linkType: hard