diff --git a/src/Shift-ClassInstaller/ShiftClassInstaller.class.st b/src/Shift-ClassInstaller/ShiftClassInstaller.class.st
index e2e18fd48b7..669190c9c71 100644
--- a/src/Shift-ClassInstaller/ShiftClassInstaller.class.st
+++ b/src/Shift-ClassInstaller/ShiftClassInstaller.class.st
@@ -76,7 +76,7 @@ ShiftClassInstaller >> copyClassSlotsFromExistingClass [
 ShiftClassInstaller >> copyObject: oldObject to: newClass [
 	| newObject hiddenSlots |
 	
-	(newObject := (newClass isVariable) and: [oldClass isVariable])
+	newObject := (newClass isVariable and: [oldClass isVariable])
 		ifTrue: [ newClass basicNew: oldObject size ]
 		ifFalse: [ newClass basicNew ].