diff --git a/.changeset/funny-bags-occur.md b/.changeset/funny-bags-occur.md
new file mode 100644
index 000000000000..81f89bcd0f5d
--- /dev/null
+++ b/.changeset/funny-bags-occur.md
@@ -0,0 +1,5 @@
+---
+'svelte': patch
+---
+
+fix: generate type definition with nullable types
diff --git a/packages/svelte/scripts/generate-dts.js b/packages/svelte/scripts/generate-dts.js
index fe4b70e09a61..0ecf7127dfd2 100644
--- a/packages/svelte/scripts/generate-dts.js
+++ b/packages/svelte/scripts/generate-dts.js
@@ -16,6 +16,9 @@ fs.writeFileSync('./types/compiler/interfaces.d.ts', `import '../index.js';`);
 
 await createBundle({
 	output: 'types/index.d.ts',
+	compilerOptions: {
+		strict: true
+	},
 	modules: {
 		svelte: 'src/runtime/public.d.ts',
 		'svelte/compiler': 'src/compiler/public.d.ts',