diff --git a/src/string.js b/src/string.js
index c2066d7..3e90ade 100644
--- a/src/string.js
+++ b/src/string.js
@@ -2,6 +2,7 @@ import { Int } from "./int";
 import { UnsignedInt } from "./unsigned-int";
 import {calculatePadding, slicePadding} from "./util";
 import isString from "lodash/isString";
+import isArray from "lodash/isArray";
 import includeIoMixin from './io-mixin';
 
 export class String {
@@ -21,7 +22,11 @@ export class String {
     let padding = calculatePadding(length);
     let result = io.slice(length);
     slicePadding(io, padding);
-    return result.buffer().toString('utf8');
+    return result.buffer();
+  }
+
+  readString(io) {
+    return this.read(io).toString('utf8');
   }
 
   write(value, io) {
@@ -31,20 +36,26 @@ export class String {
         `max allows is ${this._maxLength}`);
     }
 
-    if(!isString(value)) {
-      throw new Error(`XDR Write Error: ${value} is not a string,`);
+    let buffer;
+    if (isString(value)) {
+      buffer = Buffer.from(value, 'utf8');
+    } else {
+      buffer = Buffer.from(value);
     }
-    let buffer = Buffer.from(value, 'utf8');
     
     Int.write(buffer.length, io);
     io.writeBufferPadded(buffer);
   }
 
   isValid(value) {
-    if (!isString(value)) {
+    let buffer;
+    if (isString(value)) {
+      buffer = Buffer.from(value, 'utf8');
+    } else if (isArray(value) || Buffer.isBuffer(value)) {
+      buffer = Buffer.from(value);
+    } else {
       return false;
     }
-    let buffer = Buffer.from(value, 'utf8');
     return buffer.length <= this._maxLength;
   }
 }
diff --git a/test/unit/string_test.js b/test/unit/string_test.js
index dc50f93..2f23c2d 100644
--- a/test/unit/string_test.js
+++ b/test/unit/string_test.js
@@ -6,12 +6,24 @@ let subject = new XDR.String(4);
 describe('String#read', function() {
 
   it('decodes correctly', function() {
-    expect(read([0x00,0x00,0x00,0x00])).to.eql("");
-    expect(read([0x00,0x00,0x00,0x01,0x41,0x00,0x00,0x00])).to.eql("A");
-    expect(read([0x00,0x00,0x00,0x03,0xe4,0xb8,0x89,0x00])).to.eql("三");
-    expect(read([0x00,0x00,0x00,0x02,0x41,0x41,0x00,0x00])).to.eql("AA");
+    expect(read([0x00,0x00,0x00,0x00]).toString('utf8')).to.eql("");
+    expect(read([0x00,0x00,0x00,0x01,0x41,0x00,0x00,0x00]).toString('utf8')).to.eql("A");
+    expect(read([0x00,0x00,0x00,0x03,0xe4,0xb8,0x89,0x00]).toString('utf8')).to.eql("三");
+    expect(read([0x00,0x00,0x00,0x02,0x41,0x41,0x00,0x00]).toString('utf8')).to.eql("AA");
   });
 
+  it('decodes correctly to string', function() {
+    expect(readString([0x00,0x00,0x00,0x00])).to.eql("");
+    expect(readString([0x00,0x00,0x00,0x01,0x41,0x00,0x00,0x00])).to.eql("A");
+    expect(readString([0x00,0x00,0x00,0x03,0xe4,0xb8,0x89,0x00])).to.eql("三");
+    expect(readString([0x00,0x00,0x00,0x02,0x41,0x41,0x00,0x00])).to.eql("AA");
+  });
+
+  it('decodes non-utf-8 correctly', function() {
+    let val = read([0x00,0x00,0x00,0x01,0xd1,0x00,0x00,0x00])
+    expect(val[0]).to.eql(0xd1);
+  })
+
   it("throws a read error when the encoded length is greater than the allowed max", function() {
     expect(() => read([0x00,0x00,0x00,0x05,0x41,0x41,0x41,0x41,0x41])).to.throw(/read error/i);
   });
@@ -26,17 +38,30 @@ describe('String#read', function() {
     let io = new Cursor(bytes);
     return subject.read(io);
   }
+
+  function readString(bytes) {
+    let io = new Cursor(bytes);
+    return subject.readString(io);
+  }
 });
 
 describe('String#write', function() {
 
-  it('encodes correctly', function() {
+  it('encodes string correctly', function() {
     expect(write("")).to.eql([0x00,0x00,0x00,0x00]);
     expect(write("三")).to.eql([0x00,0x00,0x00,0x03,0xe4,0xb8,0x89,0x00]);
     expect(write("A")).to.eql([0x00,0x00,0x00,0x01,0x41,0x00,0x00,0x00]);
     expect(write("AA")).to.eql([0x00,0x00,0x00,0x02,0x41,0x41,0x00,0x00]);
   });
 
+  it('encodes non-utf-8 correctly', function() {
+    expect(write([0xd1])).to.eql([0x00,0x00,0x00,0x01,0xd1,0x00,0x00,0x00]);
+  });
+
+  it('encodes non-utf-8 correctly (buffer)', function() {
+    expect(write(Buffer.from([0xd1]))).to.eql([0x00,0x00,0x00,0x01,0xd1,0x00,0x00,0x00]);
+  });
+
   function write(value) {
     let io = new Cursor(8);
     subject.write(value, io);
@@ -51,15 +76,30 @@ describe('String#isValid', function() {
     expect(subject.isValid("aa")).to.be.true;
   });
 
+  it('returns true for arrays of the correct length', function() {
+    expect(subject.isValid([0x01])).to.be.true;
+  });
+
+  it('returns true for buffers of the correct length', function() {
+    expect(subject.isValid(Buffer.from([0x01]))).to.be.true;
+  });
+
   it('returns false for strings that are too large', function() {
     expect(subject.isValid("aaaaa")).to.be.false;
   });
 
-  it('returns false for non string', function() {
+  it('returns false for arrays that are too large', function() {
+    expect(subject.isValid([0x01, 0x01, 0x01, 0x01, 0x01])).to.be.false;
+  });
+
+  it('returns false for buffers that are too large', function() {
+    expect(subject.isValid(Buffer.from([0x01, 0x01, 0x01, 0x01, 0x01]))).to.be.false;
+  });
+
+  it('returns false for non string/array/buffer', function() {
     expect(subject.isValid(true)).to.be.false;
     expect(subject.isValid(null)).to.be.false;
     expect(subject.isValid(3)).to.be.false;
-    expect(subject.isValid([0])).to.be.false;
   });
 });