diff --git a/README.md b/README.md
index ccec8767..b5ae07f0 100644
--- a/README.md
+++ b/README.md
@@ -172,3 +172,12 @@ client.getUser(req, (err, user) => { /* ... */ });
 For a sample of the generated protos and service definitions, see [examples](https://github.com/improbable-eng/ts-protoc-gen/tree/master/examples).
 
 To generate the examples from protos, please run `./generate.sh`
+
+## Gotchas
+By default the google-protobuf library will use the JavaScript number type to store 64bit float and integer values; this can lead to overflow problems as you exceed JavaScript's `Number.MAX_VALUE`. To work around this, you should consider using the `jstype` annotation on any 64bit fields, ie:
+
+```proto
+message Example {
+  uint64 bigInt = 1 [jstype = JS_STRING];
+}
+```
\ No newline at end of file
diff --git a/examples/generated/proto/examplecom/annotations_pb.d.ts b/examples/generated/proto/examplecom/annotations_pb.d.ts
new file mode 100644
index 00000000..2c0f3e2d
--- /dev/null
+++ b/examples/generated/proto/examplecom/annotations_pb.d.ts
@@ -0,0 +1,41 @@
+// package: examplecom
+// file: proto/examplecom/annotations.proto
+
+import * as jspb from "google-protobuf";
+
+export class AnnotatedMessage extends jspb.Message {
+  getMyunit64(): string;
+  setMyunit64(value: string): void;
+
+  getMyint64(): string;
+  setMyint64(value: string): void;
+
+  getMyfixed64(): string;
+  setMyfixed64(value: string): void;
+
+  getMysint64(): string;
+  setMysint64(value: string): void;
+
+  getMysfixed64(): string;
+  setMysfixed64(value: string): void;
+
+  serializeBinary(): Uint8Array;
+  toObject(includeInstance?: boolean): AnnotatedMessage.AsObject;
+  static toObject(includeInstance: boolean, msg: AnnotatedMessage): AnnotatedMessage.AsObject;
+  static extensions: {[key: number]: jspb.ExtensionFieldInfo<jspb.Message>};
+  static extensionsBinary: {[key: number]: jspb.ExtensionFieldBinaryInfo<jspb.Message>};
+  static serializeBinaryToWriter(message: AnnotatedMessage, writer: jspb.BinaryWriter): void;
+  static deserializeBinary(bytes: Uint8Array): AnnotatedMessage;
+  static deserializeBinaryFromReader(message: AnnotatedMessage, reader: jspb.BinaryReader): AnnotatedMessage;
+}
+
+export namespace AnnotatedMessage {
+  export type AsObject = {
+    myunit64: string,
+    myint64: string,
+    myfixed64: string,
+    mysint64: string,
+    mysfixed64: string,
+  }
+}
+
diff --git a/examples/generated/proto/examplecom/annotations_pb.js b/examples/generated/proto/examplecom/annotations_pb.js
new file mode 100644
index 00000000..c0698227
--- /dev/null
+++ b/examples/generated/proto/examplecom/annotations_pb.js
@@ -0,0 +1,265 @@
+/**
+ * @fileoverview
+ * @enhanceable
+ * @suppress {messageConventions} JS Compiler reports an error if a variable or
+ *     field starts with 'MSG_' and isn't a translatable message.
+ * @public
+ */
+// GENERATED CODE -- DO NOT EDIT!
+
+var jspb = require('google-protobuf');
+var goog = jspb;
+var global = Function('return this')();
+
+goog.exportSymbol('proto.examplecom.AnnotatedMessage', null, global);
+
+/**
+ * Generated by JsPbCodeGenerator.
+ * @param {Array=} opt_data Optional initial data array, typically from a
+ * server response, or constructed directly in Javascript. The array is used
+ * in place and becomes part of the constructed object. It is not cloned.
+ * If no data is provided, the constructed object will be empty, but still
+ * valid.
+ * @extends {jspb.Message}
+ * @constructor
+ */
+proto.examplecom.AnnotatedMessage = function(opt_data) {
+  jspb.Message.initialize(this, opt_data, 0, -1, null, null);
+};
+goog.inherits(proto.examplecom.AnnotatedMessage, jspb.Message);
+if (goog.DEBUG && !COMPILED) {
+  proto.examplecom.AnnotatedMessage.displayName = 'proto.examplecom.AnnotatedMessage';
+}
+
+
+if (jspb.Message.GENERATE_TO_OBJECT) {
+/**
+ * Creates an object representation of this proto suitable for use in Soy templates.
+ * Field names that are reserved in JavaScript and will be renamed to pb_name.
+ * To access a reserved field use, foo.pb_<name>, eg, foo.pb_default.
+ * For the list of reserved names please see:
+ *     com.google.apps.jspb.JsClassTemplate.JS_RESERVED_WORDS.
+ * @param {boolean=} opt_includeInstance Whether to include the JSPB instance
+ *     for transitional soy proto support: http://goto/soy-param-migration
+ * @return {!Object}
+ */
+proto.examplecom.AnnotatedMessage.prototype.toObject = function(opt_includeInstance) {
+  return proto.examplecom.AnnotatedMessage.toObject(opt_includeInstance, this);
+};
+
+
+/**
+ * Static version of the {@see toObject} method.
+ * @param {boolean|undefined} includeInstance Whether to include the JSPB
+ *     instance for transitional soy proto support:
+ *     http://goto/soy-param-migration
+ * @param {!proto.examplecom.AnnotatedMessage} msg The msg instance to transform.
+ * @return {!Object}
+ * @suppress {unusedLocalVariables} f is only used for nested messages
+ */
+proto.examplecom.AnnotatedMessage.toObject = function(includeInstance, msg) {
+  var f, obj = {
+    myunit64: jspb.Message.getFieldWithDefault(msg, 1, "0"),
+    myint64: jspb.Message.getFieldWithDefault(msg, 2, "0"),
+    myfixed64: jspb.Message.getFieldWithDefault(msg, 3, "0"),
+    mysint64: jspb.Message.getFieldWithDefault(msg, 4, "0"),
+    mysfixed64: jspb.Message.getFieldWithDefault(msg, 5, "0")
+  };
+
+  if (includeInstance) {
+    obj.$jspbMessageInstance = msg;
+  }
+  return obj;
+};
+}
+
+
+/**
+ * Deserializes binary data (in protobuf wire format).
+ * @param {jspb.ByteSource} bytes The bytes to deserialize.
+ * @return {!proto.examplecom.AnnotatedMessage}
+ */
+proto.examplecom.AnnotatedMessage.deserializeBinary = function(bytes) {
+  var reader = new jspb.BinaryReader(bytes);
+  var msg = new proto.examplecom.AnnotatedMessage;
+  return proto.examplecom.AnnotatedMessage.deserializeBinaryFromReader(msg, reader);
+};
+
+
+/**
+ * Deserializes binary data (in protobuf wire format) from the
+ * given reader into the given message object.
+ * @param {!proto.examplecom.AnnotatedMessage} msg The message object to deserialize into.
+ * @param {!jspb.BinaryReader} reader The BinaryReader to use.
+ * @return {!proto.examplecom.AnnotatedMessage}
+ */
+proto.examplecom.AnnotatedMessage.deserializeBinaryFromReader = function(msg, reader) {
+  while (reader.nextField()) {
+    if (reader.isEndGroup()) {
+      break;
+    }
+    var field = reader.getFieldNumber();
+    switch (field) {
+    case 1:
+      var value = /** @type {string} */ (reader.readUint64String());
+      msg.setMyunit64(value);
+      break;
+    case 2:
+      var value = /** @type {string} */ (reader.readInt64String());
+      msg.setMyint64(value);
+      break;
+    case 3:
+      var value = /** @type {string} */ (reader.readFixed64String());
+      msg.setMyfixed64(value);
+      break;
+    case 4:
+      var value = /** @type {string} */ (reader.readSint64String());
+      msg.setMysint64(value);
+      break;
+    case 5:
+      var value = /** @type {string} */ (reader.readSfixed64String());
+      msg.setMysfixed64(value);
+      break;
+    default:
+      reader.skipField();
+      break;
+    }
+  }
+  return msg;
+};
+
+
+/**
+ * Serializes the message to binary data (in protobuf wire format).
+ * @return {!Uint8Array}
+ */
+proto.examplecom.AnnotatedMessage.prototype.serializeBinary = function() {
+  var writer = new jspb.BinaryWriter();
+  proto.examplecom.AnnotatedMessage.serializeBinaryToWriter(this, writer);
+  return writer.getResultBuffer();
+};
+
+
+/**
+ * Serializes the given message to binary data (in protobuf wire
+ * format), writing to the given BinaryWriter.
+ * @param {!proto.examplecom.AnnotatedMessage} message
+ * @param {!jspb.BinaryWriter} writer
+ * @suppress {unusedLocalVariables} f is only used for nested messages
+ */
+proto.examplecom.AnnotatedMessage.serializeBinaryToWriter = function(message, writer) {
+  var f = undefined;
+  f = message.getMyunit64();
+  if (parseInt(f, 10) !== 0) {
+    writer.writeUint64String(
+      1,
+      f
+    );
+  }
+  f = message.getMyint64();
+  if (parseInt(f, 10) !== 0) {
+    writer.writeInt64String(
+      2,
+      f
+    );
+  }
+  f = message.getMyfixed64();
+  if (parseInt(f, 10) !== 0) {
+    writer.writeFixed64String(
+      3,
+      f
+    );
+  }
+  f = message.getMysint64();
+  if (parseInt(f, 10) !== 0) {
+    writer.writeSint64String(
+      4,
+      f
+    );
+  }
+  f = message.getMysfixed64();
+  if (parseInt(f, 10) !== 0) {
+    writer.writeSfixed64String(
+      5,
+      f
+    );
+  }
+};
+
+
+/**
+ * optional uint64 myUnit64 = 1;
+ * @return {string}
+ */
+proto.examplecom.AnnotatedMessage.prototype.getMyunit64 = function() {
+  return /** @type {string} */ (jspb.Message.getFieldWithDefault(this, 1, "0"));
+};
+
+
+/** @param {string} value */
+proto.examplecom.AnnotatedMessage.prototype.setMyunit64 = function(value) {
+  jspb.Message.setProto3StringIntField(this, 1, value);
+};
+
+
+/**
+ * optional int64 myInt64 = 2;
+ * @return {string}
+ */
+proto.examplecom.AnnotatedMessage.prototype.getMyint64 = function() {
+  return /** @type {string} */ (jspb.Message.getFieldWithDefault(this, 2, "0"));
+};
+
+
+/** @param {string} value */
+proto.examplecom.AnnotatedMessage.prototype.setMyint64 = function(value) {
+  jspb.Message.setProto3StringIntField(this, 2, value);
+};
+
+
+/**
+ * optional fixed64 myFixed64 = 3;
+ * @return {string}
+ */
+proto.examplecom.AnnotatedMessage.prototype.getMyfixed64 = function() {
+  return /** @type {string} */ (jspb.Message.getFieldWithDefault(this, 3, "0"));
+};
+
+
+/** @param {string} value */
+proto.examplecom.AnnotatedMessage.prototype.setMyfixed64 = function(value) {
+  jspb.Message.setProto3StringIntField(this, 3, value);
+};
+
+
+/**
+ * optional sint64 mySint64 = 4;
+ * @return {string}
+ */
+proto.examplecom.AnnotatedMessage.prototype.getMysint64 = function() {
+  return /** @type {string} */ (jspb.Message.getFieldWithDefault(this, 4, "0"));
+};
+
+
+/** @param {string} value */
+proto.examplecom.AnnotatedMessage.prototype.setMysint64 = function(value) {
+  jspb.Message.setProto3StringIntField(this, 4, value);
+};
+
+
+/**
+ * optional sfixed64 mySfixed64 = 5;
+ * @return {string}
+ */
+proto.examplecom.AnnotatedMessage.prototype.getMysfixed64 = function() {
+  return /** @type {string} */ (jspb.Message.getFieldWithDefault(this, 5, "0"));
+};
+
+
+/** @param {string} value */
+proto.examplecom.AnnotatedMessage.prototype.setMysfixed64 = function(value) {
+  jspb.Message.setProto3StringIntField(this, 5, value);
+};
+
+
+goog.object.extend(exports, proto.examplecom);
diff --git a/examples/generated/proto/examplecom/annotations_pb_service.d.ts b/examples/generated/proto/examplecom/annotations_pb_service.d.ts
new file mode 100644
index 00000000..414651f0
--- /dev/null
+++ b/examples/generated/proto/examplecom/annotations_pb_service.d.ts
@@ -0,0 +1,3 @@
+// package: examplecom
+// file: proto/examplecom/annotations.proto
+
diff --git a/examples/generated/proto/examplecom/annotations_pb_service.js b/examples/generated/proto/examplecom/annotations_pb_service.js
new file mode 100644
index 00000000..414651f0
--- /dev/null
+++ b/examples/generated/proto/examplecom/annotations_pb_service.js
@@ -0,0 +1,3 @@
+// package: examplecom
+// file: proto/examplecom/annotations.proto
+
diff --git a/package-lock.json b/package-lock.json
index 0a646d85..3ab159c1 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -291,9 +291,9 @@
       }
     },
     "google-protobuf": {
-      "version": "3.5.0",
-      "resolved": "https://registry.npmjs.org/google-protobuf/-/google-protobuf-3.5.0.tgz",
-      "integrity": "sha1-uMxjx02DRXvYqakEUDyO+ya8ozk="
+      "version": "3.6.1",
+      "resolved": "https://registry.npmjs.org/google-protobuf/-/google-protobuf-3.6.1.tgz",
+      "integrity": "sha512-SJYemeX5GjDLPnadcmCNQePQHCS4Hl5fOcI/JawqDIYFhCmrtYAjcx/oTQx/Wi8UuCuZQhfvftbmPePPAYHFtA=="
     },
     "growl": {
       "version": "1.10.5",
diff --git a/package.json b/package.json
index cf0b2ac6..15dc1ed1 100644
--- a/package.json
+++ b/package.json
@@ -29,7 +29,7 @@
   "author": "Improbable",
   "license": "Apache-2.0",
   "dependencies": {
-    "google-protobuf": "^3.5.0"
+    "google-protobuf": "^3.6.1"
   },
   "devDependencies": {
     "@types/chai": "^3.5.2",
diff --git a/proto/examplecom/annotations.proto b/proto/examplecom/annotations.proto
new file mode 100644
index 00000000..5cd6fbc7
--- /dev/null
+++ b/proto/examplecom/annotations.proto
@@ -0,0 +1,11 @@
+syntax = "proto3";
+
+package examplecom;
+
+message AnnotatedMessage {
+  uint64 myUnit64 = 1 [jstype = JS_STRING];
+  int64 myInt64 = 2 [jstype = JS_STRING];
+  fixed64 myFixed64 = 3 [jstype = JS_STRING];
+  sint64 mySint64 = 4 [jstype = JS_STRING];
+  sfixed64 mySfixed64 = 5 [jstype = JS_STRING];
+}
diff --git a/src/ts/message.ts b/src/ts/message.ts
index a1485901..58639b1c 100644
--- a/src/ts/message.ts
+++ b/src/ts/message.ts
@@ -3,12 +3,16 @@ import {
   withinNamespaceFromExportEntry, normaliseFieldObjectName
 } from "../util";
 import {ExportMap} from "../ExportMap";
-import {FieldDescriptorProto, FileDescriptorProto, DescriptorProto} from "google-protobuf/google/protobuf/descriptor_pb";
+import {
+  FieldDescriptorProto, FileDescriptorProto, DescriptorProto,
+  FieldOptions
+} from "google-protobuf/google/protobuf/descriptor_pb";
 import {MESSAGE_TYPE, BYTES_TYPE, ENUM_TYPE, getFieldType, getTypeName} from "./FieldTypes";
 import {Printer} from "../Printer";
 import {printEnum} from "./enum";
 import {printOneOfDecl} from "./oneof";
 import {printExtension} from "./extensions";
+import JSType = FieldOptions.JSType;
 
 function hasFieldPresence(field: FieldDescriptorProto, fileDescriptor: FileDescriptorProto): boolean {
   if (field.getLabel() === FieldDescriptorProto.Label.LABEL_REPEATED) {
@@ -104,7 +108,20 @@ export function printMessage(fileName: string, exportMap: ExportMap, messageDesc
         exportType = filePathToPseudoNamespace(fieldEnumType.fileName) + "." + withinNamespace;
       }
     } else {
-      exportType = getTypeName(type);
+      if (field.getOptions() && field.getOptions().hasJstype()) {
+        switch (field.getOptions().getJstype()) {
+          case JSType.JS_NUMBER:
+            exportType = "number";
+            break;
+          case JSType.JS_STRING:
+            exportType = "string";
+            break;
+          default:
+            exportType = getTypeName(type);
+        }
+      } else {
+        exportType = getTypeName(type);
+      }
     }
 
     let hasClearMethod = false;
diff --git a/test/integration/annotations.ts b/test/integration/annotations.ts
new file mode 100644
index 00000000..1061efac
--- /dev/null
+++ b/test/integration/annotations.ts
@@ -0,0 +1,24 @@
+import { assert } from "chai";
+import { AnnotatedMessage } from "../../examples/generated/proto/examplecom/annotations_pb";
+
+describe("annotations", () => {
+  it("should detect and honor the `jstype` annotation", () => {
+    const unsafeInteger = Number.MAX_VALUE.toString() + "9999";
+    const msg = new AnnotatedMessage();
+
+    msg.setMyfixed64(unsafeInteger);
+    assert.strictEqual(msg.getMyfixed64(), unsafeInteger);
+
+    msg.setMyunit64(unsafeInteger);
+    assert.strictEqual(msg.getMyunit64(), unsafeInteger);
+
+    msg.setMyint64(unsafeInteger);
+    assert.strictEqual(msg.getMyint64(), unsafeInteger);
+
+    msg.setMysfixed64(unsafeInteger);
+    assert.strictEqual(msg.getMysfixed64(), unsafeInteger);
+
+    msg.setMysint64(unsafeInteger);
+    assert.strictEqual(msg.getMysint64(), unsafeInteger);
+  });
+});