diff --git a/org.modeldriven.alf.bundle/META-INF/MANIFEST.MF b/org.modeldriven.alf.bundle/META-INF/MANIFEST.MF
index 887599f83..0aacd7fe0 100644
--- a/org.modeldriven.alf.bundle/META-INF/MANIFEST.MF
+++ b/org.modeldriven.alf.bundle/META-INF/MANIFEST.MF
@@ -1,6 +1,6 @@
 Manifest-Version: 1.0
 Automatic-Module-Name: org.modeldriven.alf.bundle
-Bnd-LastModified: 1603405265284
+Bnd-LastModified: 1603460602370
 Build-Jdk: 1.8.0_31
 Built-By: seidewitz
 Bundle-ClassPath: .,jars/org.modeldriven.alf-1.0.0-SNAPSHOT.jar
@@ -8,7 +8,7 @@ Bundle-ManifestVersion: 2
 Bundle-Name: org.modeldriven.alf.bundle
 Bundle-RequiredExecutionEnvironment: JavaSE-1.8
 Bundle-SymbolicName: org.modeldriven.alf.bundle
-Bundle-Version: 1.0.0.20201022222050
+Bundle-Version: 1.0.0.20201023134244
 Created-By: Apache Maven Bundle Plugin
 Embed-Dependency: *;scope=compile;groupId=!org.modeldriven
 Embed-Directory: jars
diff --git a/org.modeldriven.alf.eclipse.moka/dist/fuml-eclipse.jar b/org.modeldriven.alf.eclipse.moka/dist/fuml-eclipse.jar
index 229239e49..6ce4d05f9 100644
Binary files a/org.modeldriven.alf.eclipse.moka/dist/fuml-eclipse.jar and b/org.modeldriven.alf.eclipse.moka/dist/fuml-eclipse.jar differ
diff --git a/org.modeldriven.alf.eclipse/dist/alf-eclipse.jar b/org.modeldriven.alf.eclipse/dist/alf-eclipse.jar
index 870866ba5..5af5cc7ce 100644
Binary files a/org.modeldriven.alf.eclipse/dist/alf-eclipse.jar and b/org.modeldriven.alf.eclipse/dist/alf-eclipse.jar differ
diff --git a/org.modeldriven.alf.eclipse/dist/fuml-eclipse.jar b/org.modeldriven.alf.eclipse/dist/fuml-eclipse.jar
index 229239e49..6ce4d05f9 100644
Binary files a/org.modeldriven.alf.eclipse/dist/fuml-eclipse.jar and b/org.modeldriven.alf.eclipse/dist/fuml-eclipse.jar differ
diff --git a/org.modeldriven.alf.fuml.impl.bundle/META-INF/MANIFEST.MF b/org.modeldriven.alf.fuml.impl.bundle/META-INF/MANIFEST.MF
index c09f96eac..3d036589c 100644
--- a/org.modeldriven.alf.fuml.impl.bundle/META-INF/MANIFEST.MF
+++ b/org.modeldriven.alf.fuml.impl.bundle/META-INF/MANIFEST.MF
@@ -1,6 +1,6 @@
 Manifest-Version: 1.0
 Automatic-Module-Name: org.modeldriven.alf.fuml.impl.bundle
-Bnd-LastModified: 1603405266256
+Bnd-LastModified: 1603460603513
 Build-Jdk: 1.8.0_31
 Built-By: seidewitz
 Bundle-ClassPath: .,jars/org.modeldriven.alf-1.0.0-SNAPSHOT.jar,jars/org
@@ -9,7 +9,7 @@ Bundle-ManifestVersion: 2
 Bundle-Name: org.modeldriven.alf.fuml.impl.bundle
 Bundle-RequiredExecutionEnvironment: JavaSE-1.8
 Bundle-SymbolicName: org.modeldriven.alf.fuml.impl.bundle
-Bundle-Version: 1.0.0.20201022222050
+Bundle-Version: 1.0.0.20201023134244
 Created-By: Apache Maven Bundle Plugin
 Embed-Dependency: *;scope=compile;groupId=!org.modeldriven
 Embed-Directory: jars
diff --git a/org.modeldriven.alf.fuml.impl/dist/alf.jar b/org.modeldriven.alf.fuml.impl/dist/alf.jar
index 84a374a63..7b16f2bff 100644
Binary files a/org.modeldriven.alf.fuml.impl/dist/alf.jar and b/org.modeldriven.alf.fuml.impl/dist/alf.jar differ
diff --git a/org.modeldriven.alf/dist/alf-base.jar b/org.modeldriven.alf/dist/alf-base.jar
index 9254385d1..895f4fb7b 100644
Binary files a/org.modeldriven.alf/dist/alf-base.jar and b/org.modeldriven.alf/dist/alf-base.jar differ
diff --git a/org.modeldriven.alf/src/org/modeldriven/alf/syntax/expressions/impl/TupleImpl.java b/org.modeldriven.alf/src/org/modeldriven/alf/syntax/expressions/impl/TupleImpl.java
index d9b4df267..93be5c3ad 100644
--- a/org.modeldriven.alf/src/org/modeldriven/alf/syntax/expressions/impl/TupleImpl.java
+++ b/org.modeldriven.alf/src/org/modeldriven/alf/syntax/expressions/impl/TupleImpl.java
@@ -302,6 +302,10 @@ public Map<String, AssignedSource> getAssignmentsAfterMap(ElementReference refer
                 if (lhs != null) {
                     lhs.getImpl().setAssignmentBefore(assignmentsBefore);
                     lhs.getImpl().setCurrentScope(this.currentScope);
+                    
+                    // NOTE: Force recomputation of LHS referent, in case 
+                    // derived LHS already existed.
+                   	lhs.getImpl().setReferent(null);
 
                     ElementReference parameter = 
                             invocation.getImpl().parameterNamed(output.getName(), referent);