diff --git a/.changeset/hip-actors-wink.md b/.changeset/hip-actors-wink.md
new file mode 100644
index 00000000..842de257
--- /dev/null
+++ b/.changeset/hip-actors-wink.md
@@ -0,0 +1,5 @@
+---
+'@conform-to/zod': minor
+---
+
+fix number and bigint coercion
diff --git a/packages/conform-zod/coercion.ts b/packages/conform-zod/coercion.ts
index a6a8cd63..db584981 100644
--- a/packages/conform-zod/coercion.ts
+++ b/packages/conform-zod/coercion.ts
@@ -119,7 +119,7 @@ export function enableTypeCoercion<Schema extends ZodTypeAny>(
 		schema = any()
 			.transform((value) =>
 				coerceString(value, (text) =>
-					text.trim() === '' ? Number.NaN : Number(text),
+					text.trim() === '' ? text : Number(text),
 				),
 			)
 			.pipe(type);
@@ -132,14 +132,14 @@ export function enableTypeCoercion<Schema extends ZodTypeAny>(
 	} else if (def.typeName === 'ZodDate') {
 		schema = any()
 			.transform((value) =>
-				coerceString(value, (timestamp) => {
-					const date = new Date(timestamp);
+				coerceString(value, (text) => {
+					const date = new Date(text);
 
 					// z.date() does not expose a quick way to set invalid_date error
 					// This gets around it by returning the original string if it's invalid
 					// See https://github.com/colinhacks/zod/issues/1526
 					if (isNaN(date.getTime())) {
-						return timestamp;
+						return text;
 					}
 
 					return date;
@@ -148,7 +148,18 @@ export function enableTypeCoercion<Schema extends ZodTypeAny>(
 			.pipe(type);
 	} else if (def.typeName === 'ZodBigInt') {
 		schema = any()
-			.transform((value) => coerceString(value, BigInt))
+			.transform((value) =>
+				coerceString(value, (text) => {
+					if (text.trim() === '') {
+						return text;
+					}
+					try {
+						return BigInt(text);
+					} catch {
+						return text;
+					}
+				}),
+			)
 			.pipe(type);
 	} else if (def.typeName === 'ZodArray') {
 		schema = any()
diff --git a/tests/conform-zod.spec.ts b/tests/conform-zod.spec.ts
index d642f1dc..124be2c0 100644
--- a/tests/conform-zod.spec.ts
+++ b/tests/conform-zod.spec.ts
@@ -405,6 +405,74 @@ describe('conform-zod', () => {
 			});
 		});
 
+		test('z.bigint', () => {
+			const schema = z.object({
+				test: z
+					.bigint({ required_error: 'required', invalid_type_error: 'invalid' })
+					.min(1n, 'min')
+					.max(10n, 'max')
+					.multipleOf(2n, 'step'),
+			});
+			const file = new File([], '');
+
+			expect(parseWithZod(createFormData([]), { schema })).toEqual({
+				status: 'error',
+				payload: {},
+				error: { test: ['required'] },
+				reply: expect.any(Function),
+			});
+			expect(
+				parseWithZod(createFormData([['test', '']]), {
+					schema,
+				}),
+			).toEqual({
+				status: 'error',
+				payload: { test: '' },
+				error: { test: ['required'] },
+				reply: expect.any(Function),
+			});
+			expect(
+				parseWithZod(createFormData([['test', 'abc']]), {
+					schema,
+				}),
+			).toEqual({
+				status: 'error',
+				payload: { test: 'abc' },
+				error: { test: ['invalid'] },
+				reply: expect.any(Function),
+			});
+			expect(
+				parseWithZod(createFormData([['test', file]]), {
+					schema,
+				}),
+			).toEqual({
+				status: 'error',
+				payload: { test: file },
+				error: { test: ['invalid'] },
+				reply: expect.any(Function),
+			});
+			expect(
+				parseWithZod(createFormData([['test', '5']]), {
+					schema,
+				}),
+			).toEqual({
+				status: 'error',
+				payload: { test: '5' },
+				error: { test: ['step'] },
+				reply: expect.any(Function),
+			});
+			expect(
+				parseWithZod(createFormData([['test', ' ']]), {
+					schema,
+				}),
+			).toEqual({
+				status: 'error',
+				payload: { test: ' ' },
+				error: { test: ['invalid'] },
+				reply: expect.any(Function),
+			});
+		});
+
 		test('z.date', () => {
 			const schema = z.object({
 				test: z