diff --git a/packages/concerto-core/lib/serializer/jsonpopulator.js b/packages/concerto-core/lib/serializer/jsonpopulator.js
index 891bf9c37..5ca8781e3 100644
--- a/packages/concerto-core/lib/serializer/jsonpopulator.js
+++ b/packages/concerto-core/lib/serializer/jsonpopulator.js
@@ -211,9 +211,18 @@ class JSONPopulator {
      * @private
      */
     processMapType(mapDeclaration, parameters, value, type) {
-        let decl = mapDeclaration.getModelFile()
-            .getAllDeclarations()
-            .find(decl => decl.name === type);
+        let decl;
+        if (value && typeof value === 'object' && value.$class) {
+            // Use the $class property to find the class declaration
+            decl = mapDeclaration.getModelFile()
+                .getAllDeclarations()
+                .find(decl => decl.getFullyQualifiedName() === value.$class);
+        } else {
+            // Fallback to the original type lookup if value is not an object or doesn't have $class
+            decl = mapDeclaration.getModelFile()
+                .getAllDeclarations()
+                .find(decl => decl.name === type);
+        }
 
         // if its a ClassDeclaration, populate the Concept.
         if (decl?.isClassDeclaration()) {
diff --git a/packages/concerto-core/test/serializer/jsonpopulator.js b/packages/concerto-core/test/serializer/jsonpopulator.js
index e7ddc8a38..89e22c36c 100644
--- a/packages/concerto-core/test/serializer/jsonpopulator.js
+++ b/packages/concerto-core/test/serializer/jsonpopulator.js
@@ -75,6 +75,20 @@ describe('JSONPopulator', () => {
                 o String assetId
             }
         `);
+        modelManager.addCTOModel(`
+            namespace org.acme.abstract
+            abstract asset Asset3 {
+                o String assetId
+            }
+            asset Asset4 extends Asset3 {}
+            map AssetByName {
+                o String 
+                o Asset3 
+            }
+            concept MyContainerAsset3 {
+                o AssetByName assetByName
+            }
+        `);
         assetDeclaration1 = modelManager.getType('org.acme.MyContainerAsset1').getProperty('myAsset');
         relationshipDeclaration1 = modelManager.getType('org.acme.MyTx1').getProperty('myAsset');
         relationshipDeclaration2 = modelManager.getType('org.acme.MyTx2').getProperty('myAssets');
@@ -479,6 +493,29 @@ describe('JSONPopulator', () => {
                 jsonPopulator.visit(modelManager.getType('org.acme.MyContainerAsset2'), options);
             }).should.throw(/Expected value at path `\$.rootObj.myAssets\[0\].assetValue` to be of type `Integer`/);
         });
+
+        it('should be able to deserialise a map that uses abstract types as values', () => {
+            let options = {
+                jsonStack: new TypedStack({
+                    $class: 'org.acme.abstract.MyContainerAsset3',
+                    assetByName: {
+                        'asset3': {
+                            $class: 'org.acme.abstract.Asset4'
+                        }
+                    }
+                }),
+                resourceStack: new TypedStack({}),
+                factory: mockFactory,
+                modelManager: modelManager
+            };
+
+            let mockResource1 = sinon.createStubInstance(Resource);
+            mockFactory.newResource.withArgs('org.acme.abstract', 'MyAsset4', 'asset3').returns(mockResource1);
+            (() => {
+                jsonPopulator.visit(modelManager.getType('org.acme.abstract.MyContainerAsset3'), options);
+            }).should.not.throw();
+        });
+
     });
 
     describe('#visitField', () => {