diff --git a/packages/actions/package.json b/packages/actions/package.json
index 1ffb00fe6..916ecb8a9 100644
--- a/packages/actions/package.json
+++ b/packages/actions/package.json
@@ -49,7 +49,7 @@
 		"meilisearch": "^0.38.0",
 		"p-limit": "^5.0.0",
 		"tslib": "^2.6.2",
-		"undici": "6.18.2"
+		"undici": "6.21.1"
 	},
 	"devDependencies": {
 		"@types/node": "18.18.8",
diff --git a/packages/discord.js/package.json b/packages/discord.js/package.json
index 8528751a6..a624efd6d 100644
--- a/packages/discord.js/package.json
+++ b/packages/discord.js/package.json
@@ -76,7 +76,7 @@
     "fast-deep-equal": "3.1.3",
     "lodash.snakecase": "4.1.1",
     "tslib": "2.6.2",
-    "undici": "6.18.2"
+    "undici": "6.21.1"
   },
   "devDependencies": {
     "@discordjs/api-extractor": "workspace:^",
diff --git a/packages/proxy/package.json b/packages/proxy/package.json
index 8b4bdd9a7..6cb25ef0e 100644
--- a/packages/proxy/package.json
+++ b/packages/proxy/package.json
@@ -68,7 +68,7 @@
 		"@discordjs/rest": "workspace:^",
 		"@discordjs/util": "workspace:^",
 		"tslib": "^2.6.2",
-		"undici": "6.18.2"
+		"undici": "6.21.1"
 	},
 	"devDependencies": {
 		"@discordjs/api-extractor": "workspace:^",
diff --git a/packages/rest/package.json b/packages/rest/package.json
index 040f519f1..4b961232d 100644
--- a/packages/rest/package.json
+++ b/packages/rest/package.json
@@ -91,7 +91,7 @@
 		"discord-api-types": "^0.37.119",
 		"magic-bytes.js": "^1.10.0",
 		"tslib": "^2.6.2",
-		"undici": "6.18.2"
+		"undici": "6.21.1"
 	},
 	"devDependencies": {
 		"@discordjs/api-extractor": "workspace:^",
diff --git a/packages/scripts/package.json b/packages/scripts/package.json
index 7f2104b5d..901a23259 100644
--- a/packages/scripts/package.json
+++ b/packages/scripts/package.json
@@ -68,7 +68,7 @@
 		"@vercel/postgres": "^0.8.0",
 		"commander": "^12.1.0",
 		"tslib": "^2.6.2",
-		"undici": "6.18.2",
+		"undici": "6.21.1",
 		"yaml": "2.4.3"
 	},
 	"devDependencies": {
diff --git a/packages/ws/package.json b/packages/ws/package.json
index af309d007..1129fdb24 100644
--- a/packages/ws/package.json
+++ b/packages/ws/package.json
@@ -100,7 +100,7 @@
 		"tsup": "^8.1.0",
 		"turbo": "^1.13.3",
 		"typescript": "^5.4.5",
-		"undici": "6.18.2",
+		"undici": "6.21.1",
 		"vitest": "^1.6.0",
 		"zlib-sync": "^0.1.9"
 	},
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 85d727fe6..b29292ea0 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -411,8 +411,8 @@ importers:
         specifier: ^2.6.2
         version: 2.6.2
       undici:
-        specifier: 6.18.2
-        version: 6.18.2
+        specifier: 6.21.1
+        version: 6.21.1
     devDependencies:
       '@types/node':
         specifier: 18.18.8
@@ -953,8 +953,8 @@ importers:
         specifier: 2.6.2
         version: 2.6.2
       undici:
-        specifier: 6.18.2
-        version: 6.18.2
+        specifier: 6.21.1
+        version: 6.21.1
     devDependencies:
       '@discordjs/api-extractor':
         specifier: workspace:^
@@ -1194,8 +1194,8 @@ importers:
         specifier: ^2.6.2
         version: 2.6.2
       undici:
-        specifier: 6.18.2
-        version: 6.18.2
+        specifier: 6.21.1
+        version: 6.21.1
     devDependencies:
       '@discordjs/api-extractor':
         specifier: workspace:^
@@ -1316,8 +1316,8 @@ importers:
         specifier: ^2.6.2
         version: 2.6.2
       undici:
-        specifier: 6.18.2
-        version: 6.18.2
+        specifier: 6.21.1
+        version: 6.21.1
     devDependencies:
       '@discordjs/api-extractor':
         specifier: workspace:^
@@ -1395,8 +1395,8 @@ importers:
         specifier: ^2.6.2
         version: 2.6.2
       undici:
-        specifier: 6.18.2
-        version: 6.18.2
+        specifier: 6.21.1
+        version: 6.21.1
       yaml:
         specifier: 2.4.3
         version: 2.4.3
@@ -1759,8 +1759,8 @@ importers:
         specifier: ^5.4.5
         version: 5.4.5
       undici:
-        specifier: 6.18.2
-        version: 6.18.2
+        specifier: 6.21.1
+        version: 6.21.1
       vitest:
         specifier: ^1.6.0
         version: 1.6.0(@edge-runtime/vm@3.2.0)(@types/node@18.17.9)(happy-dom@14.12.0)(terser@5.31.0)
@@ -13297,14 +13297,14 @@ packages:
     resolution: {integrity: sha512-72RFADWFqKmUb2hmmvNODKL3p9hcB6Gt2DOQMis1SEBaV6a4MH8soBvzg+95CYhCKPFedut2JY9bMfrDl9D23g==}
     engines: {node: '>=14.0'}
 
-  undici@6.18.2:
-    resolution: {integrity: sha512-o/MQLTwRm9IVhOqhZ0NQ9oXax1ygPjw6Vs+Vq/4QRjbOAC3B1GCHy7TYxxbExKlb7bzDRzt9vBWU6BDz0RFfYg==}
-    engines: {node: '>=18.17'}
-
   undici@6.19.8:
     resolution: {integrity: sha512-U8uCCl2x9TK3WANvmBavymRzxbfFYG+tAu+fgx3zxQy3qdagQqBLwJVrdyO1TBfUXvfKveMKJZhpvUYoOjM+4g==}
     engines: {node: '>=18.17'}
 
+  undici@6.21.1:
+    resolution: {integrity: sha512-q/1rj5D0/zayJB2FraXdaWxbhWiNKDvu8naDT2dl1yTlvJp4BLtOcp2a5BvgGNQpYYJzau7tf1WgKv3b+7mqpQ==}
+    engines: {node: '>=18.17'}
+
   unicode-canonical-property-names-ecmascript@2.0.0:
     resolution: {integrity: sha512-yY5PpDlfVIU5+y/BSCxAJRBIS1Zc2dDG3Ujq+sR0U+JjUevW2JhocOF+soROYDSaAezOzOKuyyixhD6mBknSmQ==}
     engines: {node: '>=4'}
@@ -29784,10 +29784,10 @@ snapshots:
     dependencies:
       '@fastify/busboy': 2.1.1
 
-  undici@6.18.2: {}
-
   undici@6.19.8: {}
 
+  undici@6.21.1: {}
+
   unicode-canonical-property-names-ecmascript@2.0.0: {}
 
   unicode-match-property-ecmascript@2.0.0: