diff --git a/package.json b/package.json
index b981d0d..0a12eb1 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "gawk",
-  "version": "4.6.5",
+  "version": "4.6.6",
   "description": "Observable JavaScript object model",
   "main": "./dist/index.js",
   "author": "Chris Barber <chris@cb1inc.com> (https://github.com/cb1kenobi)",
diff --git a/src/index.js b/src/index.js
index 44b84dd..07bb25b 100644
--- a/src/index.js
+++ b/src/index.js
@@ -421,7 +421,7 @@ function copyListeners(dest, src, compareFn) {
 		return;
 	}
 
-	for (const key of Object.getOwnPropertyNames(dest)) {
+	for (const key of [ ...Object.getOwnPropertySymbols(dest), ...Object.getOwnPropertyNames(dest) ]) {
 		if (key === '__gawk__') {
 			continue;
 		}
@@ -500,7 +500,7 @@ export function set(dest, src, compareFn) {
 
 			const tmp = {};
 
-			for (const key of Object.getOwnPropertyNames(src)) {
+			for (const key of [ ...Object.getOwnPropertySymbols(src), ...Object.getOwnPropertyNames(src) ]) {
 				if (key === '__gawk__') {
 					continue;
 				}
@@ -519,7 +519,7 @@ export function set(dest, src, compareFn) {
 			}
 
 			// prune the existing object, then copy all the properties from our temp object
-			for (const key of Object.getOwnPropertyNames(dest)) {
+			for (const key of [ ...Object.getOwnPropertySymbols(dest), ...Object.getOwnPropertyNames(dest) ]) {
 				if (key !== '__gawk__') {
 					delete dest[key];
 				}
@@ -682,7 +682,7 @@ function mix(objs, deep) {
 	 * @param {Object} src - The source object to copy from.
 	 */
 	const mixer = (gobj, src) => {
-		for (const key of Object.getOwnPropertyNames(src)) {
+		for (const key of [ ...Object.getOwnPropertySymbols(src), ...Object.getOwnPropertyNames(src) ]) {
 			if (key === '__gawk__') {
 				continue;
 			}
diff --git a/test/test-object.js b/test/test-object.js
index ab998fd..4ee9ef1 100644
--- a/test/test-object.js
+++ b/test/test-object.js
@@ -249,10 +249,12 @@ describe('set property', () => {
 
 		const gobj = gawk({});
 		gobj[id] = 'foo';
-		expect(gobj).to.deep.equal({ [id]: 'foo' });
+		expect(Object.getOwnPropertySymbols(gobj)).to.deep.equal([ id ]);
+		expect(gobj[id]).to.equal('foo');
 
 		gobj[id] = 'bar';
-		expect(gobj).to.deep.equal({ [id]: 'bar' });
+		expect(Object.getOwnPropertySymbols(gobj)).to.deep.equal([ id ]);
+		expect(gobj[id]).to.equal('bar');
 	});
 });
 
@@ -296,13 +298,22 @@ describe('Object.keys()', () => {
 });
 
 describe('Object.getOwnPropertySymbols()', () => {
-	it('should return an array of symbol keys in the object', () => {
+	it('should return an array of symbol keys in empty object', () => {
 		const id = Symbol();
 
-		const gobj = gawk({ [id]: 'foo' });
-		expect(gobj).to.deep.equal({ [id]: 'foo' });
+		const gobj = gawk({});
+		expect(Object.getOwnPropertySymbols(gobj)).to.deep.equal([]);
+
+		gobj[id] = 'foo';
+		expect(Object.getOwnPropertySymbols(gobj)).to.deep.equal([ id ]);
+	});
 
+	it('should return an array of symbol keys from initialized object', () => {
+		const id = Symbol();
+
+		const gobj = gawk({ [id]: 'foo' });
 		expect(Object.getOwnPropertySymbols(gobj)).to.deep.equal([ id ]);
+		expect(gobj[id]).to.equal('foo');
 	});
 });
 
@@ -396,11 +407,14 @@ describe('gawk.merge()', () => {
 	it('should merge an object with a symbol property', () => {
 		const id = Symbol();
 
-		const gobj = gawk({ [id]: 'foo' });
-		expect(gobj).to.deep.equal({ [id]: 'foo' });
+		const gobj = gawk({});
+		gobj[id] = 'foo';
+		expect(Object.getOwnPropertySymbols(gobj)).to.deep.equal([ id ]);
+		expect(gobj[id]).to.equal('foo');
 
 		gawk.merge(gobj, { [id]: 'bar' });
-		expect(gobj).to.deep.equal({ [id]: 'bar' });
+		expect(Object.getOwnPropertySymbols(gobj)).to.deep.equal([ id ]);
+		expect(gobj[id]).to.equal('bar');
 	});
 });
 
diff --git a/test/test-set.js b/test/test-set.js
index 33862ce..7f8ad71 100644
--- a/test/test-set.js
+++ b/test/test-set.js
@@ -391,13 +391,25 @@ describe('gawk.set()', () => {
 		expect(counter).to.equal(2);
 	});
 
-	it('should set an object with a symbol property', () => {
+	it('should set an existing object with a symbol property', () => {
+		const id = Symbol();
+
+		const gobj = gawk({});
+
+		gawk.set(gobj, { [id]: 'foo' });
+		expect(Object.getOwnPropertySymbols(gobj)).to.deep.equal([ id ]);
+		expect(gobj[id]).to.equal('foo');
+	});
+
+	it('should set an existing object with a symbol property', () => {
 		const id = Symbol();
 
 		const gobj = gawk({ [id]: 'foo' });
-		expect(gobj).to.deep.equal({ [id]: 'foo' });
+		expect(Object.getOwnPropertySymbols(gobj)).to.deep.equal([ id ]);
+		expect(gobj[id]).to.equal('foo');
 
 		gawk.set(gobj, { [id]: 'bar' });
-		expect(gobj).to.deep.equal({ [id]: 'bar' });
+		expect(Object.getOwnPropertySymbols(gobj)).to.deep.equal([ id ]);
+		expect(gobj[id]).to.equal('bar');
 	});
 });