diff --git a/.changeset/petite-clocks-relax.md b/.changeset/petite-clocks-relax.md
new file mode 100644
index 000000000..3fe8158e1
--- /dev/null
+++ b/.changeset/petite-clocks-relax.md
@@ -0,0 +1,5 @@
+---
+'sv': patch
+---
+
+fix(cloudflare): remove commented out `Platform` placeholder when adding Cloudflare types
diff --git a/packages/sv/lib/addons/better-auth.ts b/packages/sv/lib/addons/better-auth.ts
index 116858b41..fdf12364e 100644
--- a/packages/sv/lib/addons/better-auth.ts
+++ b/packages/sv/lib/addons/better-auth.ts
@@ -156,7 +156,7 @@ export default defineAddon({
 		});
 
 		sv.file('src/app.d.ts', (content) => {
-			const { ast, generateCode } = parse.script(content);
+			const { ast, comments, generateCode } = parse.script(content);
 
 			js.imports.addNamed(ast, {
 				imports: ['User', 'Session'],
@@ -169,6 +169,9 @@ export default defineAddon({
 				throw new Error('Failed detecting `locals` interface in `src/app.d.ts`');
 			}
 
+			// remove the commented out placeholder since we're adding the real one
+			comments.remove((c) => c.type === 'Line' && c.value.trim() === 'interface Locals {}');
+
 			const user = locals.body.body.find((prop) =>
 				js.common.hasTypeProperty(prop, { name: 'user' })
 			);
@@ -176,37 +179,11 @@ export default defineAddon({
 				js.common.hasTypeProperty(prop, { name: 'session' })
 			);
 
-			function addProps(
-				name: string,
-				value: string,
-				optional = false
-			): AstTypes.TSInterfaceBody['body'][number] {
-				return {
-					type: 'TSPropertySignature',
-					key: {
-						type: 'Identifier',
-						name
-					},
-					computed: false,
-					optional,
-					typeAnnotation: {
-						type: 'TSTypeAnnotation',
-						typeAnnotation: {
-							type: 'TSTypeReference',
-							typeName: {
-								type: 'Identifier',
-								name: value
-							}
-						}
-					}
-				};
-			}
-
 			if (!user) {
-				locals.body.body.push(addProps('user', 'User', true));
+				locals.body.body.push(js.common.createTypeProperty('user', 'User', true));
 			}
 			if (!session) {
-				locals.body.body.push(addProps('session', 'Session', true));
+				locals.body.body.push(js.common.createTypeProperty('session', 'Session', true));
 			}
 			return generateCode();
 		});
diff --git a/packages/sv/lib/addons/sveltekit-adapter.ts b/packages/sv/lib/addons/sveltekit-adapter.ts
index 994335bef..5c64bfa74 100644
--- a/packages/sv/lib/addons/sveltekit-adapter.ts
+++ b/packages/sv/lib/addons/sveltekit-adapter.ts
@@ -1,7 +1,6 @@
 import { readFileSync } from 'node:fs';
 import { join } from 'node:path';
 import {
-	type AstTypes,
 	defineAddon,
 	defineAddonOptions,
 	js,
@@ -211,18 +210,21 @@ export default defineAddon({
 				});
 
 				sv.file('src/app.d.ts', (content) => {
-					const { ast, generateCode } = parse.script(content);
+					const { ast, comments, generateCode } = parse.script(content);
 
 					const platform = js.kit.addGlobalAppInterface(ast, { name: 'Platform' });
 					if (!platform) {
 						throw new Error('Failed detecting `platform` interface in `src/app.d.ts`');
 					}
 
+					// remove the commented out placeholder since we're adding the real one
+					comments.remove((c) => c.type === 'Line' && c.value.trim() === 'interface Platform {}');
+
 					platform.body.body.push(
-						createCloudflarePlatformType('env', 'Env'),
-						createCloudflarePlatformType('ctx', 'ExecutionContext'),
-						createCloudflarePlatformType('caches', 'CacheStorage'),
-						createCloudflarePlatformType('cf', 'IncomingRequestCfProperties', true)
+						js.common.createTypeProperty('env', 'Env'),
+						js.common.createTypeProperty('ctx', 'ExecutionContext'),
+						js.common.createTypeProperty('caches', 'CacheStorage'),
+						js.common.createTypeProperty('cf', 'IncomingRequestCfProperties', true)
 					);
 
 					return generateCode();
@@ -244,29 +246,3 @@ export default defineAddon({
 		return toReturn;
 	}
 });
-
-function createCloudflarePlatformType(
-	name: string,
-	value: string,
-	optional = false
-): AstTypes.TSInterfaceBody['body'][number] {
-	return {
-		type: 'TSPropertySignature',
-		key: {
-			type: 'Identifier',
-			name
-		},
-		computed: false,
-		optional,
-		typeAnnotation: {
-			type: 'TSTypeAnnotation',
-			typeAnnotation: {
-				type: 'TSTypeReference',
-				typeName: {
-					type: 'Identifier',
-					name: value
-				}
-			}
-		}
-	};
-}
diff --git a/packages/sv/lib/cli/tests/snapshots/create-with-all-addons/src/app.d.ts b/packages/sv/lib/cli/tests/snapshots/create-with-all-addons/src/app.d.ts
index 64ed26a98..87f8dbd97 100644
--- a/packages/sv/lib/cli/tests/snapshots/create-with-all-addons/src/app.d.ts
+++ b/packages/sv/lib/cli/tests/snapshots/create-with-all-addons/src/app.d.ts
@@ -7,7 +7,6 @@ declare global {
 		interface Locals { user?: User; session?: Session }
 
 		// interface Error {}
-		// interface Locals {}
 		// interface PageData {}
 		// interface PageState {}
 		// interface Platform {}
diff --git a/packages/sv/lib/core/tests/js/common/create-type-property/input.ts b/packages/sv/lib/core/tests/js/common/create-type-property/input.ts
new file mode 100644
index 000000000..943dd0c93
--- /dev/null
+++ b/packages/sv/lib/core/tests/js/common/create-type-property/input.ts
@@ -0,0 +1,7 @@
+declare global {
+	namespace App {
+		// interface Platform {}
+	}
+}
+
+export {};
diff --git a/packages/sv/lib/core/tests/js/common/create-type-property/output.ts b/packages/sv/lib/core/tests/js/common/create-type-property/output.ts
new file mode 100644
index 000000000..09d6ad1bc
--- /dev/null
+++ b/packages/sv/lib/core/tests/js/common/create-type-property/output.ts
@@ -0,0 +1,13 @@
+declare global {
+	namespace App {
+		interface Platform {
+			env: Env;
+			ctx: ExecutionContext;
+			cf?: IncomingRequestCfProperties
+		}
+
+		// interface Platform {}
+	}
+}
+
+export {};
diff --git a/packages/sv/lib/core/tests/js/common/create-type-property/run.ts b/packages/sv/lib/core/tests/js/common/create-type-property/run.ts
new file mode 100644
index 000000000..40dbb38a7
--- /dev/null
+++ b/packages/sv/lib/core/tests/js/common/create-type-property/run.ts
@@ -0,0 +1,10 @@
+import { common, kit, type AstTypes } from '../../../../tooling/js/index.ts';
+
+export function run(ast: AstTypes.Program): void {
+	const platform = kit.addGlobalAppInterface(ast as AstTypes.TSProgram, { name: 'Platform' });
+	platform.body.body.push(
+		common.createTypeProperty('env', 'Env'),
+		common.createTypeProperty('ctx', 'ExecutionContext'),
+		common.createTypeProperty('cf', 'IncomingRequestCfProperties', true)
+	);
+}
diff --git a/packages/sv/lib/core/tooling/js/common.ts b/packages/sv/lib/core/tooling/js/common.ts
index eb6cab28a..038b668a9 100644
--- a/packages/sv/lib/core/tooling/js/common.ts
+++ b/packages/sv/lib/core/tooling/js/common.ts
@@ -192,3 +192,29 @@ export function hasTypeProperty(
 		node.key.name === options.name
 	);
 }
+
+export function createTypeProperty(
+	name: string,
+	value: string,
+	optional = false
+): AstTypes.TSInterfaceBody['body'][number] {
+	return {
+		type: 'TSPropertySignature',
+		key: {
+			type: 'Identifier',
+			name
+		},
+		computed: false,
+		optional,
+		typeAnnotation: {
+			type: 'TSTypeAnnotation',
+			typeAnnotation: {
+				type: 'TSTypeReference',
+				typeName: {
+					type: 'Identifier',
+					name: value
+				}
+			}
+		}
+	};
+}