diff --git a/packages/protobuf/src/codegen-info.ts b/packages/protobuf/src/codegen-info.ts
index fd737ecd9..1f325678d 100644
--- a/packages/protobuf/src/codegen-info.ts
+++ b/packages/protobuf/src/codegen-info.ts
@@ -75,6 +75,7 @@ type RuntimeSymbolName =
   | "proto3"
   | "Message"
   | "PartialMessage"
+  | "PartialStrictMessage"
   | "PlainMessage"
   | "FieldList"
   | "MessageType"
@@ -116,6 +117,7 @@ export const codegenInfo: CodegenInfo = {
     proto3:               {typeOnly: false, privateImportPath: "./proto3.js",        publicImportPath: packageName},
     Message:              {typeOnly: false, privateImportPath: "./message.js",       publicImportPath: packageName},
     PartialMessage:       {typeOnly: true,  privateImportPath: "./message.js",       publicImportPath: packageName},
+    PartialStrictMessage: {typeOnly: true,  privateImportPath: "./message.js",       publicImportPath: packageName},
     PlainMessage:         {typeOnly: true,  privateImportPath: "./message.js",       publicImportPath: packageName},
     FieldList:            {typeOnly: true,  privateImportPath: "./field-list.js",    publicImportPath: packageName},
     MessageType:          {typeOnly: true,  privateImportPath: "./message-type.js",  publicImportPath: packageName},
diff --git a/packages/protobuf/src/index.ts b/packages/protobuf/src/index.ts
index 0a07feab7..add914e53 100644
--- a/packages/protobuf/src/index.ts
+++ b/packages/protobuf/src/index.ts
@@ -21,7 +21,12 @@ export { protoDelimited } from "./proto-delimited.js";
 export { codegenInfo } from "./codegen-info.js";
 
 export { Message } from "./message.js";
-export type { AnyMessage, PartialMessage, PlainMessage } from "./message.js";
+export type {
+  AnyMessage,
+  PartialMessage,
+  PartialStrictMessage,
+  PlainMessage,
+} from "./message.js";
 export { isMessage } from "./is-message.js";
 
 export type { FieldInfo, OneofInfo } from "./field.js";
diff --git a/packages/protobuf/src/message.ts b/packages/protobuf/src/message.ts
index cc9d3a1f1..d78c37a53 100644
--- a/packages/protobuf/src/message.ts
+++ b/packages/protobuf/src/message.ts
@@ -204,6 +204,22 @@ export type PartialMessage<T extends Message<T>> = {
   [P in keyof T as T[P] extends Function ? never : P]?: PartialField<T[P]>;
 };
 
+export type PartialStrictMessage<T extends Message<T>> = {
+  // eslint-disable-next-line @typescript-eslint/ban-types -- we use `Function` to identify methods
+  [P in keyof T as T[P] extends Function ? never : P]: PartialStrictField<T[P]>;
+};
+
+// prettier-ignore
+type PartialStrictField<F> =
+  F extends (Date | Uint8Array | bigint | boolean | string | number) ? F
+  : F extends Array<infer U> ? Array<PartialField<U>>
+  : F extends ReadonlyArray<infer U> ? ReadonlyArray<PartialField<U>>
+  : F extends Message<infer U> ? PartialStrictMessage<U>
+  : F extends OneofSelectedMessage<infer C, infer V> ? {case: C; value: PartialStrictMessage<V>}
+  : F extends { case: string | undefined; value?: unknown; } ? F
+  : F extends {[key: string|number]: Message<infer U>} ? {[key: string|number]: PartialStrictMessage<U>}
+  : F ;
+
 // prettier-ignore
 type PartialField<F> =
   F extends (Date | Uint8Array | bigint | boolean | string | number) ? F
diff --git a/packages/protoc-gen-es/src/declaration.ts b/packages/protoc-gen-es/src/declaration.ts
index 9c648891d..b0f2e3634 100644
--- a/packages/protoc-gen-es/src/declaration.ts
+++ b/packages/protoc-gen-es/src/declaration.ts
@@ -64,10 +64,11 @@ function generateEnum(schema: Schema, f: GeneratedFile, enumeration: DescEnum) {
 function generateMessage(schema: Schema, f: GeneratedFile, message: DescMessage) {
   const protoN = getNonEditionRuntime(schema, message.file);
   const {
-    PartialMessage,
     FieldList,
     Message,
     PlainMessage,
+    PartialStrictMessage,
+    PartialMessage,
     BinaryReadOptions,
     JsonReadOptions,
     JsonValue
@@ -86,7 +87,7 @@ function generateMessage(schema: Schema, f: GeneratedFile, message: DescMessage)
     }
     f.print();
   }
-  f.print("  constructor(data?: ", PartialMessage, "<", m, ">);");
+  f.print("  constructor(data?: ", schema.strict ? PartialStrictMessage : PartialMessage, "<", m, ">);");
   f.print();
   generateWktMethods(schema, f, message);
   f.print("  static readonly runtime: typeof ", protoN, ";");
@@ -125,7 +126,7 @@ function generateOneof(schema: Schema, f: GeneratedFile, oneof: DescOneof) {
       f.print(`  } | {`);
     }
     f.print(f.jsDoc(field, "    "));
-    const { typing } = getFieldTypeInfo(field);
+    const { typing } = getFieldTypeInfo(field, schema.strict);
     f.print(`    value: `, typing, `;`);
     f.print(`    case: "`, localName(field), `";`);
   }
@@ -136,7 +137,7 @@ function generateOneof(schema: Schema, f: GeneratedFile, oneof: DescOneof) {
 function generateField(schema: Schema, f: GeneratedFile, field: DescField) {
     f.print(f.jsDoc(field, "  "));
     const e: Printable = [];
-    const { typing, optional } = getFieldTypeInfo(field);
+    const { typing, optional } = getFieldTypeInfo(field, schema.strict);
     if (!optional) {
         e.push("  ", localName(field), ": ", typing, ";");
     } else {
@@ -151,7 +152,7 @@ function generateExtension(
   f: GeneratedFile,
   ext: DescExtension,
 ) {
-  const { typing } = getFieldTypeInfo(ext);
+  const { typing } = getFieldTypeInfo(ext, schema.strict);
   const e = f.import(ext.extendee).toTypeOnly();
   f.print(f.jsDoc(ext));
   f.print(f.exportDecl("declare const", localName(ext)), ": ", schema.runtime.Extension, "<", e, ", ", typing, ">;");
@@ -232,7 +233,7 @@ function generateWktStaticMethods(schema: Schema, f: GeneratedFile, message: Des
     case "google.protobuf.BoolValue":
     case "google.protobuf.StringValue":
     case "google.protobuf.BytesValue": {
-      const {typing} = getFieldTypeInfo(ref.value);
+      const {typing} = getFieldTypeInfo(ref.value, schema.strict);
       f.print("  static readonly fieldWrapper: {")
       f.print("    wrapField(value: ", typing, "): ", message, ",")
       f.print("    unwrapField(value: ", message, "): ", typing, ",")
diff --git a/packages/protoc-gen-es/src/typescript.ts b/packages/protoc-gen-es/src/typescript.ts
index 0d2b7bc90..3f2a66af7 100644
--- a/packages/protoc-gen-es/src/typescript.ts
+++ b/packages/protoc-gen-es/src/typescript.ts
@@ -74,6 +74,7 @@ function generateMessage(schema: Schema, f: GeneratedFile, message: DescMessage)
   const protoN = getNonEditionRuntime(schema, message.file);
   const {
     PartialMessage,
+    PartialStrictMessage,
     FieldList,
     Message,
     PlainMessage,
@@ -94,7 +95,7 @@ function generateMessage(schema: Schema, f: GeneratedFile, message: DescMessage)
     }
     f.print();
   }
-  f.print("  constructor(data?: ", PartialMessage, "<", message, ">) {");
+  f.print("  constructor(data?: ", schema.strict ? PartialStrictMessage : PartialMessage, "<", message, ">) {");
   f.print("    super();");
   f.print("    ", protoN, ".util.initPartial(data, this);");
   f.print("  }");
@@ -148,7 +149,7 @@ function generateOneof(schema: Schema, f: GeneratedFile, oneof: DescOneof) {
       f.print(`  } | {`);
     }
     f.print(f.jsDoc(field, "    "));
-    const { typing } = getFieldTypeInfo(field);
+    const { typing } = getFieldTypeInfo(field, schema.strict);
     f.print(`    value: `, typing, `;`);
     f.print(`    case: "`, localName(field), `";`);
   }
@@ -159,7 +160,7 @@ function generateOneof(schema: Schema, f: GeneratedFile, oneof: DescOneof) {
 function generateField(schema: Schema, f: GeneratedFile, field: DescField) {
   f.print(f.jsDoc(field, "  "));
   const e: Printable = [];
-  const { typing, optional, typingInferrableFromZeroValue } = getFieldTypeInfo(field);
+  const { typing, optional, typingInferrableFromZeroValue } = getFieldTypeInfo(field, schema.strict);
   if (optional) {
     e.push("  ", localName(field), "?: ", typing, ";");
   } else {
@@ -184,7 +185,7 @@ function generateExtension(
   ext: DescExtension,
 ) {
   const protoN = getNonEditionRuntime(schema, ext.file);
-  const { typing } = getFieldTypeInfo(ext);
+  const { typing } = getFieldTypeInfo(ext, schema.strict);
   f.print(f.jsDoc(ext));
   f.print(f.exportDecl("const", ext), " = ", protoN, ".makeExtension<", ext.extendee, ", ", typing, ">(");
   f.print("  ", f.string(ext.typeName), ", ");
@@ -651,7 +652,7 @@ function generateWktStaticMethods(schema: Schema, f: GeneratedFile, message: Des
     case "google.protobuf.BoolValue":
     case "google.protobuf.StringValue":
     case "google.protobuf.BytesValue": {
-      const {typing} = getFieldTypeInfo(ref.value);
+      const {typing} = getFieldTypeInfo(ref.value, schema.strict);
       f.print("  static readonly fieldWrapper = {")
       f.print("    wrapField(value: ", typing, "): ", message, " {")
       f.print("      return new ", message, "({value});")
diff --git a/packages/protoc-gen-es/src/util.ts b/packages/protoc-gen-es/src/util.ts
index 5fa1f5a6a..5a63d2045 100644
--- a/packages/protoc-gen-es/src/util.ts
+++ b/packages/protoc-gen-es/src/util.ts
@@ -25,7 +25,10 @@ import {
 import type { Printable } from "@bufbuild/protoplugin/ecmascript";
 import { localName } from "@bufbuild/protoplugin/ecmascript";
 
-export function getFieldTypeInfo(field: DescField | DescExtension): {
+export function getFieldTypeInfo(
+  field: DescField | DescExtension,
+  strict: boolean,
+): {
   typing: Printable;
   optional: boolean;
   typingInferrableFromZeroValue: boolean;
@@ -38,7 +41,7 @@ export function getFieldTypeInfo(field: DescField | DescExtension): {
       typing.push(scalarTypeScriptType(field.scalar, field.longType));
       optional =
         field.optional ||
-        field.proto.label === FieldDescriptorProto_Label.REQUIRED;
+        (!strict && field.proto.label === FieldDescriptorProto_Label.REQUIRED);
       typingInferrableFromZeroValue = true;
       break;
     case "message": {
@@ -64,7 +67,7 @@ export function getFieldTypeInfo(field: DescField | DescExtension): {
       });
       optional =
         field.optional ||
-        field.proto.label === FieldDescriptorProto_Label.REQUIRED;
+        (!strict && field.proto.label === FieldDescriptorProto_Label.REQUIRED);
       typingInferrableFromZeroValue = true;
       break;
     case "map": {
diff --git a/packages/protoplugin/src/ecmascript/parameter.ts b/packages/protoplugin/src/ecmascript/parameter.ts
index 3ae8bda2f..979fbb592 100644
--- a/packages/protoplugin/src/ecmascript/parameter.ts
+++ b/packages/protoplugin/src/ecmascript/parameter.ts
@@ -25,6 +25,7 @@ export interface ParsedParameter {
   importExtension: string;
   jsImportStyle: "module" | "legacy_commonjs";
   sanitizedParameter: string;
+  strict: boolean;
 }
 
 export function parseParameter(
@@ -38,6 +39,7 @@ export function parseParameter(
   const rewriteImports: RewriteImports = [];
   let importExtension = ".js";
   let jsImportStyle: "module" | "legacy_commonjs" = "module";
+  let strict = false;
   const rawParameters: string[] = [];
   for (const { key, value, raw } of splitParameter(parameter)) {
     // Whether this key/value plugin parameter pair should be
@@ -135,6 +137,21 @@ export function parseParameter(
         }
         break;
       }
+      case "strict": {
+        switch (value) {
+          case "true":
+          case "1":
+            strict = true;
+            break;
+          case "false":
+          case "0":
+            strict = false;
+            break;
+          default:
+            throw new PluginOptionError(raw);
+        }
+        break;
+      }
       default:
         if (parseExtraOption === undefined) {
           throw new PluginOptionError(raw);
@@ -154,6 +171,7 @@ export function parseParameter(
   const sanitizedParameter = rawParameters.join(",");
 
   return {
+    strict,
     targets,
     tsNocheck,
     bootstrapWkt,
diff --git a/packages/protoplugin/src/ecmascript/runtime-imports.ts b/packages/protoplugin/src/ecmascript/runtime-imports.ts
index 28fed57f1..43699a142 100644
--- a/packages/protoplugin/src/ecmascript/runtime-imports.ts
+++ b/packages/protoplugin/src/ecmascript/runtime-imports.ts
@@ -21,6 +21,7 @@ export interface RuntimeImports {
   proto3: ImportSymbol;
   Message: ImportSymbol;
   PartialMessage: ImportSymbol;
+  PartialStrictMessage: ImportSymbol;
   PlainMessage: ImportSymbol;
   FieldList: ImportSymbol;
   MessageType: ImportSymbol;
@@ -47,6 +48,7 @@ export function createRuntimeImports(bootstrapWkt: boolean): RuntimeImports {
     proto3:                infoToSymbol("proto3",               bootstrapWkt),
     Message:               infoToSymbol("Message",              bootstrapWkt),
     PartialMessage:        infoToSymbol("PartialMessage",       bootstrapWkt),
+    PartialStrictMessage:  infoToSymbol("PartialStrictMessage", bootstrapWkt),
     PlainMessage:          infoToSymbol("PlainMessage",         bootstrapWkt),
     FieldList:             infoToSymbol("FieldList",            bootstrapWkt),
     MessageType:           infoToSymbol("MessageType",          bootstrapWkt),
diff --git a/packages/protoplugin/src/ecmascript/schema.ts b/packages/protoplugin/src/ecmascript/schema.ts
index a9994d849..ca2114e3a 100644
--- a/packages/protoplugin/src/ecmascript/schema.ts
+++ b/packages/protoplugin/src/ecmascript/schema.ts
@@ -78,6 +78,11 @@ export interface Schema {
    * The original google.protobuf.compiler.CodeGeneratorRequest.
    */
   readonly proto: CodeGeneratorRequest;
+
+  /**
+   * strict mode with `required` support
+   */
+  readonly strict: boolean;
 }
 
 interface SchemaController extends Schema {
@@ -120,6 +125,7 @@ export function createSchema(
   const generatedFiles: GeneratedFileController[] = [];
   return {
     targets: parameter.targets,
+    strict: parameter.strict,
     runtime,
     proto: request,
     files: filesToGenerate,