diff --git a/package-lock.json b/package-lock.json
index 0a604d0..dbb07a7 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -14,10 +14,10 @@
         "prettier": "^2.2.1",
         "ts-jest": "^26.4.4",
         "typescript": "^4.7.4",
-        "zod": "^3.20.5"
+        "zod": "^3.22.4"
       },
       "peerDependencies": {
-        "fast-check": "^2.23.0",
+        "fast-check": ">2.23.0 <4.0.0",
         "zod": "^3.18.0"
       }
     },
@@ -6209,9 +6209,9 @@
       }
     },
     "node_modules/zod": {
-      "version": "3.20.5",
-      "resolved": "https://registry.npmjs.org/zod/-/zod-3.20.5.tgz",
-      "integrity": "sha512-BTAAliwfoB9dWf2hC+TXlyWKk/YTqRGZjHQR0WLC2A2pzierWo7KuQ1ebjS4SNaFaxg/lDItzl9/QTgLjcHbgw==",
+      "version": "3.22.4",
+      "resolved": "https://registry.npmjs.org/zod/-/zod-3.22.4.tgz",
+      "integrity": "sha512-iC+8Io04lddc+mVqQ9AZ7OQ2MrUKGN+oIQyq1vemgt46jwCwLfhq7/pwnBnNXXXZb8VTVLKwp9EDkx+ryxIWmg==",
       "dev": true,
       "funding": {
         "url": "https://github.com/sponsors/colinhacks"
@@ -11046,9 +11046,9 @@
       "dev": true
     },
     "zod": {
-      "version": "3.20.5",
-      "resolved": "https://registry.npmjs.org/zod/-/zod-3.20.5.tgz",
-      "integrity": "sha512-BTAAliwfoB9dWf2hC+TXlyWKk/YTqRGZjHQR0WLC2A2pzierWo7KuQ1ebjS4SNaFaxg/lDItzl9/QTgLjcHbgw==",
+      "version": "3.22.4",
+      "resolved": "https://registry.npmjs.org/zod/-/zod-3.22.4.tgz",
+      "integrity": "sha512-iC+8Io04lddc+mVqQ9AZ7OQ2MrUKGN+oIQyq1vemgt46jwCwLfhq7/pwnBnNXXXZb8VTVLKwp9EDkx+ryxIWmg==",
       "dev": true
     }
   }
diff --git a/package.json b/package.json
index 4d52628..6e70421 100644
--- a/package.json
+++ b/package.json
@@ -42,7 +42,7 @@
     "prettier": "^2.2.1",
     "ts-jest": "^26.4.4",
     "typescript": "^4.7.4",
-    "zod": "^3.20.5"
+    "zod": "^3.22.4"
   },
   "peerDependencies": {
     "fast-check": ">2.23.0 <4.0.0",
diff --git a/src/zod-fast-check.ts b/src/zod-fast-check.ts
index 7394825..060b690 100644
--- a/src/zod-fast-check.ts
+++ b/src/zod-fast-check.ts
@@ -24,6 +24,7 @@ import {
   ZodPipeline,
   ZodPromise,
   ZodRawShape,
+  ZodReadonly,
   ZodRecord,
   ZodSchema,
   ZodSet,
@@ -36,6 +37,9 @@ import {
 
 const MIN_SUCCESS_RATE = 0.01;
 
+const ZOD_EMAIL_REGEX =
+  /^(?!\.)(?!.*\.\.)([A-Z0-9_+-\.]*)[A-Z0-9_+-]@([A-Z0-9][A-Z0-9\-]*\.)+[A-Z]{2,}$/i;
+
 type UnknownZodSchema = ZodSchema<unknown, ZodTypeDef, unknown>;
 
 type SchemaToArbitrary = <Schema extends UnknownZodSchema>(
@@ -55,9 +59,12 @@ type ArbitraryBuilders = {
   >;
 };
 
-// ZodSymbol is missing from the union for first-party types, so we use this
-// type instead which includes it.
-type AllFirstPartySchemaTypes = ZodFirstPartySchemaTypes | ZodSymbol;
+// ZodSymbol and ZodReadonly are missing from the union for first-party types,
+// so we use this type instead which includes it.
+type AllFirstPartySchemaTypes =
+  | ZodFirstPartySchemaTypes
+  | ZodSymbol
+  | ZodReadonly<UnknownZodSchema>;
 
 type ExtractFirstPartySchemaType<TypeName extends ZodFirstPartyTypeKind> =
   Extract<AllFirstPartySchemaTypes, { _def: { typeName: TypeName } }>;
@@ -251,7 +258,9 @@ const arbitraryBuilders: ArbitraryBuilders = {
         case "uuid":
           return fc.uuid();
         case "email":
-          return fc.emailAddress();
+          return fc
+            .emailAddress()
+            .filter((email) => ZOD_EMAIL_REGEX.test(email));
         case "url":
           return fc.webUrl();
         case "datetime":
@@ -565,6 +574,13 @@ const arbitraryBuilders: ArbitraryBuilders = {
   ZodSymbol() {
     return fc.string().map((s) => Symbol(s));
   },
+  ZodReadonly(
+    schema: ZodReadonly<UnknownZodSchema>,
+    path: string,
+    recurse: SchemaToArbitrary
+  ) {
+    return recurse(schema._def.innerType, path);
+  },
 };
 
 export class ZodFastCheckError extends Error {}
diff --git a/tests/zod-fast-check.test.ts b/tests/zod-fast-check.test.ts
index a455a5b..0a53c6b 100644
--- a/tests/zod-fast-check.test.ts
+++ b/tests/zod-fast-check.test.ts
@@ -80,7 +80,10 @@ describe("Generate arbitraries for Zod schema input types", () => {
     "record of objects": z.record(z.object({ name: z.string() })),
     "record of strings": z.record(z.string()),
     "record of strings with min-length values": z.record(z.string().min(1)),
-    "record of strings with min-length keys": z.record(z.string().min(1), z.string()),
+    "record of strings with min-length keys": z.record(
+      z.string().min(1),
+      z.string()
+    ),
     "map with string keys": z.map(z.string(), z.number()),
     "map with object keys": z.map(
       z.object({ id: z.number() }),
@@ -156,6 +159,10 @@ describe("Generate arbitraries for Zod schema input types", () => {
     "Coerced date": z.coerce.date(),
     "string with catch": z.string().catch("fallback"),
     symbol: z.symbol(),
+    "readonly array": z.array(z.unknown()).readonly(),
+    "readonly tuple": z.tuple([z.string(), z.number()]).readonly(),
+    "readonly map": z.map(z.string(), z.date()).readonly(),
+    "readonly set": z.set(z.string()).readonly(),
   };
 
   for (const [name, schema] of Object.entries(schemas)) {
@@ -307,6 +314,17 @@ describe("Generate arbitraries for Zod schema output types", () => {
       })
     );
   });
+
+  test("readonly outputs cannot be modified", () => {
+    const schema = z.array(z.number()).readonly();
+    const arbitrary = ZodFastCheck().outputOf(schema);
+
+    return fc.assert(
+      fc.property(arbitrary, (value) => {
+        expect(() => (value as number[]).push(1)).toThrow();
+      })
+    );
+  });
 });
 
 describe("Override the arbitrary for a particular schema type", () => {