diff --git a/packages/concerto-core/lib/introspect/modelfile.js b/packages/concerto-core/lib/introspect/modelfile.js
index f582b05e6e..8012d8e8c8 100644
--- a/packages/concerto-core/lib/introspect/modelfile.js
+++ b/packages/concerto-core/lib/introspect/modelfile.js
@@ -275,19 +275,19 @@ class ModelFile extends Decorated {
         // Validate all of the types in this model file.
         // Check if names of the declarations are unique.
         const uniqueNames = new Set();
-        this.declarations.forEach(
-            d => {
-                const fqn = d.getFullyQualifiedName();
-                if (!uniqueNames.has(fqn)) {
-                    uniqueNames.add(fqn);
-                } else {
-                    throw new IllegalModelException(
-                        `Duplicate class name ${fqn}`
-                    );
-                }
+        this.declarations.forEach(d => {
+            const fqn = d.getFullyQualifiedName();
+            const shortName = ModelUtil.getShortName(fqn);
+            if (uniqueNames.has(fqn)) {
+                throw new IllegalModelException(`Duplicate class name: ${fqn}`);
             }
-        );
-
+            if (this.importShortNames.has(shortName)) {
+                throw new IllegalModelException(
+                    `TypeName Conflict: The type '${shortName}' is being redefined, but it already exists as an imported type from '${this.importShortNames.get(shortName)}'. Please rename your local type or avoid importing conflicting types.`
+                );
+            }
+            uniqueNames.add(fqn);
+        });
         // Run validations on class declarations
         for(let n=0; n < this.declarations.length; n++) {
             let classDeclaration = this.declarations[n];
diff --git a/packages/concerto-core/test/composer/composermodel.js b/packages/concerto-core/test/composer/composermodel.js
index 6bd0365e82..96cc8d82b3 100644
--- a/packages/concerto-core/test/composer/composermodel.js
+++ b/packages/concerto-core/test/composer/composermodel.js
@@ -33,16 +33,16 @@ const COMPOSER_MODEL =
  */
 namespace system
 
-event Event {
+event newEvent {
 }
 
-participant Participant {
+participant newParticipant {
 }
 
-asset Asset {
+asset newAsset {
 }
 
-transaction Transaction {
+transaction newTransaction {
 }
 
 /**
diff --git a/packages/concerto-core/test/data/parser/classdeclaration.dupeassetname.cto b/packages/concerto-core/test/data/parser/classdeclaration.dupeassetname.cto
index f58438bc7c..9ac9c8a2f4 100644
--- a/packages/concerto-core/test/data/parser/classdeclaration.dupeassetname.cto
+++ b/packages/concerto-core/test/data/parser/classdeclaration.dupeassetname.cto
@@ -14,12 +14,12 @@
 
 namespace com.testing
 
-asset Asset identified by id {
+asset newAsset identified by id {
   o String id
   o String newValue
 }
 
-asset Asset identified by id {
+asset newAsset identified by id {
   o String id
   o String newValue
 }
\ No newline at end of file
diff --git a/packages/concerto-core/test/data/parser/classdeclaration.dupeconceptname.cto b/packages/concerto-core/test/data/parser/classdeclaration.dupeconceptname.cto
index 93487093db..525cd2c12f 100644
--- a/packages/concerto-core/test/data/parser/classdeclaration.dupeconceptname.cto
+++ b/packages/concerto-core/test/data/parser/classdeclaration.dupeconceptname.cto
@@ -14,12 +14,12 @@
 
 namespace com.testing
 
-concept Concept{
+concept newConcept{
   o String id
   o String newValue
 }
 
-concept Concept{
+concept newConcept{
   o String id
   o String newValue
 }
\ No newline at end of file
diff --git a/packages/concerto-core/test/introspect/classdeclaration.js b/packages/concerto-core/test/introspect/classdeclaration.js
index 1faafe0520..a785c88ace 100644
--- a/packages/concerto-core/test/introspect/classdeclaration.js
+++ b/packages/concerto-core/test/introspect/classdeclaration.js
@@ -336,7 +336,7 @@ describe('ClassDeclaration', () => {
     describe('#_resolveSuperType', () => {
 
         it('should return Asset if no super type', () => {
-            let classDecl = modelManager.getType('system.Asset');
+            let classDecl = modelManager.getType('system.newAsset');
             classDecl._resolveSuperType().should.not.be.null;
         });
 
@@ -373,7 +373,7 @@ describe('ClassDeclaration', () => {
     describe('#getSuperTypeDeclaration', () => {
 
         it('should return Concept if no super type', () => {
-            let classDecl = modelManager.getType('system.Asset');
+            let classDecl = modelManager.getType('system.newAsset');
             classDecl.getSuperTypeDeclaration().should.not.be.null;
         });
     });
diff --git a/packages/concerto-core/test/model/concept-identified.js b/packages/concerto-core/test/model/concept-identified.js
index 656459239d..e794398425 100644
--- a/packages/concerto-core/test/model/concept-identified.js
+++ b/packages/concerto-core/test/model/concept-identified.js
@@ -42,7 +42,7 @@ describe('Concept Identifiers', function () {
             --> Product product
         }
         transaction Request {}
-        event Event {}
+        event newEvent {}
         `, 'test.cto');
         classDecl = modelManager.getType('org.accordproject.Order');
     });
@@ -98,7 +98,7 @@ describe('Concept Identifiers', function () {
             const txn = factory.newResource('org.accordproject', 'Request');
             dayjs(txn.getTimestamp()).isValid().should.be.true;
 
-            const event = factory.newResource('org.accordproject', 'Event');
+            const event = factory.newResource('org.accordproject', 'newEvent');
             dayjs(event.getTimestamp()).isValid().should.be.true;
         });