diff --git a/packages/composer-common/api.txt b/packages/composer-common/api.txt
index 59dc6b0e86..6ec6107523 100644
--- a/packages/composer-common/api.txt
+++ b/packages/composer-common/api.txt
@@ -260,7 +260,6 @@ class ModelManager {
 }
 class ReadOnlyDecorator extends Decorator {
    + void constructor(Object) throws IllegalModelException
-   + boolean getValue() 
 }
 class ReadOnlyDecoratorFactory extends DecoratorFactory {
    + Decorator newDecorator(Object) 
diff --git a/packages/composer-common/changelog.txt b/packages/composer-common/changelog.txt
index ce888d6b62..94df571d36 100644
--- a/packages/composer-common/changelog.txt
+++ b/packages/composer-common/changelog.txt
@@ -24,6 +24,9 @@
 # Note that the latest public API is documented using JSDocs and is available in api.txt.
 #
 
+Version 0.19.20 {308d962120667e982b2600107d0b8b13} 2019-01-29
+- Modify readonly decorator to be parameterless
+
 Version 0.19.20 {5ff216eab17b2d990c43636c51a585b5} 2018-12-18
 - Add readonly decorator factory
 
diff --git a/packages/composer-common/lib/readonlydecorator.js b/packages/composer-common/lib/readonlydecorator.js
index 2ce9e94ad2..b8747044e2 100644
--- a/packages/composer-common/lib/readonlydecorator.js
+++ b/packages/composer-common/lib/readonlydecorator.js
@@ -40,22 +40,9 @@ class ReadOnlyDecorator extends Decorator {
     process() {
         super.process();
         const args = this.getArguments();
-        if (args.length !== 1) {
-            throw new IllegalModelException(`@readonly decorator expects 1 argument, but ${args.length} arguments were specified.`, this.parent.getModelFile(), this.ast.location);
+        if (args.length !== 0) {
+            throw new IllegalModelException(`@readonly decorator expects 0 arguments, but ${args.length} arguments were specified.`, this.parent.getModelFile(), this.ast.location);
         }
-        const arg = args[0];
-        if (typeof arg !== 'boolean') {
-            throw new IllegalModelException(`@readonly decorator expects a boolean argument, but an argument of type ${typeof arg} was specified.`, this.parent.getModelFile(), this.ast.location);
-        }
-        this.value = arg;
-    }
-
-    /**
-     * Get the value of this commit decorator.
-     * @return {boolean} The value of this commit decorator.
-     */
-    getValue() {
-        return this.value;
     }
 
 }
diff --git a/packages/composer-common/test/businessnetworkdefinition.js b/packages/composer-common/test/businessnetworkdefinition.js
index b7010e1f91..e582d67540 100644
--- a/packages/composer-common/test/businessnetworkdefinition.js
+++ b/packages/composer-common/test/businessnetworkdefinition.js
@@ -522,7 +522,7 @@ describe('BusinessNetworkDefinition', () => {
             const modelManager = bnd.getModelManager();
             modelManager.addModelFile(`
             namespace org.acme
-            @readonly(true)
+            @readonly
             transaction T{ }`);
             const transactionDeclaration = modelManager.getType('org.acme.T');
             const decorator = transactionDeclaration.getDecorator('readonly');
diff --git a/packages/composer-common/test/readonlydecorator.js b/packages/composer-common/test/readonlydecorator.js
index 2ba289262b..5aaacc4a22 100644
--- a/packages/composer-common/test/readonlydecorator.js
+++ b/packages/composer-common/test/readonlydecorator.js
@@ -20,7 +20,7 @@ const ModelManager = require('../lib/modelmanager');
 
 require('chai').should();
 
-describe('RaedOnlyDecorator', () => {
+describe('ReadOnlyDecorator', () => {
 
     let modelManager;
     let transactionDeclaration;
@@ -37,38 +37,12 @@ describe('RaedOnlyDecorator', () => {
 
     describe('#process', () => {
 
-        it('should throw if no arguments are specified', () => {
-            (() => {
-                new ReadOnlyDecorator(transactionDeclaration, { location: { start: { offset: 0, line: 1, column: 1 }, end: { offset: 22, line: 1, column: 23 } }, name: 'readonly', arguments: { list: [] } });
-            }).should.throw(/@readonly decorator expects 1 argument, but 0 arguments were specified. Line 1 column 1, to line 1 column 23./);
-        });
-
-        it('should throw if two arguments are specified', () => {
+        it('should throw if arguments are specified', () => {
             (() => {
                 new ReadOnlyDecorator(transactionDeclaration, { location: { start: { offset: 0, line: 1, column: 1 }, end: { offset: 22, line: 1, column: 23 } }, name: 'readonly', arguments: { list: [ { value: true }, { value: false } ] } });
-            }).should.throw(/@readonly decorator expects 1 argument, but 2 arguments were specified. Line 1 column 1, to line 1 column 23./);
+            }).should.throw(/@readonly decorator expects 0 arguments, but 2 arguments were specified. Line 1 column 1, to line 1 column 23./);
         });
-
-        it('should throw if a an incorrectly typed argument is specified', () => {
-            (() => {
-                new ReadOnlyDecorator(transactionDeclaration, { location: { start: { offset: 0, line: 1, column: 1 }, end: { offset: 22, line: 1, column: 23 } }, name: 'readonly', arguments: { list: [ { value: 'hello world' } ] } });
-            }).should.throw(/@readonly decorator expects a boolean argument, but an argument of type string was specified. Line 1 column 1, to line 1 column 23./);
-        });
-
     });
 
-    describe('#getValue', () => {
-
-        it('should return true if the argument is true', () => {
-            const decorator = new ReadOnlyDecorator(transactionDeclaration, { location: { start: { offset: 0, line: 1, column: 1 }, end: { offset: 22, line: 1, column: 23 } }, name: 'readonly', arguments: { list: [ { value: true } ] } });
-            decorator.getValue().should.be.true;
-        });
-
-        it('should return false if the argument is false', () => {
-            const decorator = new ReadOnlyDecorator(transactionDeclaration, { location: { start: { offset: 0, line: 1, column: 1 }, end: { offset: 22, line: 1, column: 23 } }, name: 'readonly', arguments: { list: [ { value: false } ] } });
-            decorator.getValue().should.be.false;
-        });
-
-    });
 
 });
diff --git a/packages/composer-common/test/readonlydecoratorfactory.js b/packages/composer-common/test/readonlydecoratorfactory.js
index 35fb39035f..06d723cd29 100644
--- a/packages/composer-common/test/readonlydecoratorfactory.js
+++ b/packages/composer-common/test/readonlydecoratorfactory.js
@@ -43,7 +43,7 @@ describe('ReadOnlyDecoratorDecoratorFactory', () => {
         });
 
         it('should return a readonly decorator instance for a @readonly decorator', () => {
-            const decorator = factory.newDecorator(transactionDeclaration, { name: 'readonly', arguments: { list: [ { value: false } ] } });
+            const decorator = factory.newDecorator(transactionDeclaration, { name: 'readonly' });
             decorator.should.be.an.instanceOf(ReadOnlyDecorator);
         });
 
diff --git a/packages/composer-runtime/lib/engine.transactions.js b/packages/composer-runtime/lib/engine.transactions.js
index 8091cddb66..e8858c08bf 100644
--- a/packages/composer-runtime/lib/engine.transactions.js
+++ b/packages/composer-runtime/lib/engine.transactions.js
@@ -286,8 +286,7 @@ class EngineTransactions {
         // Get the type and resolved type.
         const transactionDeclaration = transaction.getClassDeclaration();
         const returnsDecorator = transactionDeclaration.getDecorator('returns');
-        const readOnlyDecorator = transactionDeclaration.getDecorator('readonly');
-        const readOnly = readOnlyDecorator ? readOnlyDecorator.getValue() : false;
+        const readOnly = transactionDeclaration.getDecorator('readonly') ? true : false;
         const returnValueType = returnsDecorator.getType();
         const returnValueResolvedType = returnsDecorator.getResolvedType();
         const isArray = returnsDecorator.isArray();
diff --git a/packages/composer-runtime/test/engine.transactions.js b/packages/composer-runtime/test/engine.transactions.js
index 3edf8fa884..d7e1c26b37 100644
--- a/packages/composer-runtime/test/engine.transactions.js
+++ b/packages/composer-runtime/test/engine.transactions.js
@@ -85,12 +85,12 @@ describe('EngineTransactions', () => {
 
         }
         @returns(MyAsset)
-        @readonly(true)
+        @readonly
         transaction MyTransactionThatReturnsAsset {
             o String value
         }
         @returns(MyAsset[])
-        @readonly(false)
+        @readonly
         transaction MyTransactionThatReturnsAssetArray {
             o String value
         }
@@ -342,6 +342,17 @@ describe('EngineTransactions', () => {
             })]).should.be.rejectedWith(/such error/);
         });
 
+        it('should correctly identify a readonly decorator', () => {
+            let transaction = factory.newTransaction('org.acme', 'MyTransactionThatReturnsConcept');
+            let result = transaction.getClassDeclaration().getDecorator('readonly');
+            should.not.exist(result);
+
+            transaction = factory.newTransaction('org.acme', 'MyTransactionThatReturnsAsset');
+            result = transaction.getClassDeclaration().getDecorator('readonly');
+            should.exist(result);
+            result.name.should.equal('readonly');
+        });
+
     });
 
     describe('#_executeTransaction', () => {
@@ -668,7 +679,18 @@ describe('EngineTransactions', () => {
             }]);
         });
 
-        it('should handle a readonly(true) Asset return value', () => {
+        it('should handle a concept return value that is not readonly but contains a $original component', () => {
+            const transaction = factory.newTransaction('org.acme', 'MyTransactionThatReturnsConcept');
+            const concept = factory.newConcept('org.acme', 'MyConcept');
+            concept.value = 'hello world';
+            concept.$original = 'not to be seen';
+            engine._processComplexReturnValue(mockContext, transaction, concept).should.deep.equal({
+                $class: 'org.acme.MyConcept',
+                value: 'hello world'
+            });
+        });
+
+        it('should handle a readonly Asset return value', () => {
             const transaction = factory.newTransaction('org.acme', 'MyTransactionThatReturnsAsset');
             const asset = factory.newResource('org.acme', 'MyAsset','001');
             asset.value = 'hello world';
@@ -676,21 +698,15 @@ describe('EngineTransactions', () => {
             engine._processComplexReturnValue(mockContext, transaction, asset).should.equal('penguin');
         });
 
-        it('should handle a readonly(false) Asset[] return value', () => {
+        it('should handle a readonly Asset[] return value', () => {
             const transaction = factory.newTransaction('org.acme', 'MyTransactionThatReturnsAssetArray');
             const asset1 = factory.newResource('org.acme', 'MyAsset','001');
             asset1.value = 'hello world';
+            asset1.$original = 'penguin';
             const asset2 = factory.newResource('org.acme', 'MyAsset','002');
             asset2.value = 'hello again world';
-            engine._processComplexReturnValue(mockContext, transaction, [asset1, asset2]).should.deep.equal([{
-                $class: 'org.acme.MyAsset',
-                assetId: '001',
-                value: 'hello world'
-            }, {
-                $class: 'org.acme.MyAsset',
-                assetId: '002',
-                value: 'hello again world'
-            }]);
+            asset2.$original = 'power';
+            engine._processComplexReturnValue(mockContext, transaction, [asset1, asset2]).should.deep.equal(['penguin', 'power']);
         });
 
         it('should throw for an invalid (wrong type) concept return value', () => {