diff --git a/repository/OpenPonk-Core/OPModelObjectReference.class.st b/repository/OpenPonk-Core/OPModelObjectReference.class.st
index 1b8b6945..6974af0f 100644
--- a/repository/OpenPonk-Core/OPModelObjectReference.class.st
+++ b/repository/OpenPonk-Core/OPModelObjectReference.class.st
@@ -22,9 +22,9 @@ OPModelObjectReference >> = otherModelObject [
 ]
 
 { #category : 'comparing' }
-OPModelObjectReference >> modelObjectFrom: aDictionary [
+OPModelObjectReference >> modelObjectFrom: aCollection [
 
-	^ aDictionary at: uuid
+	^ aCollection detect: [ :any | any uuid = uuid ]
 ]
 
 { #category : 'printing' }
diff --git a/repository/OpenPonk-Core/OPShape.class.st b/repository/OpenPonk-Core/OPShape.class.st
index 0a1658d1..dab3b030 100644
--- a/repository/OpenPonk-Core/OPShape.class.st
+++ b/repository/OpenPonk-Core/OPShape.class.st
@@ -426,18 +426,18 @@ OPShape >> resizableInteractionTarget [
 ]
 
 { #category : 'serialization' }
-OPShape >> resolveAllModelElements: aDictionary [
+OPShape >> resolveAllModelElements: aCollection [
 
-	self resolveModelElements: aDictionary.
+	self resolveModelElements: aCollection.
 	self ownedElements do: [ :each | 
-		each resolveAllModelElements: aDictionary ]
+		each resolveAllModelElements: aCollection ]
 ]
 
 { #category : 'serialization' }
-OPShape >> resolveModelElements: aDictionary [
+OPShape >> resolveModelElements: aCollection [
 
-	self modelElements: (self modelElements collect: [ :each | 
-			 each modelObjectFrom: aDictionary ])
+	self modelElements: (self modelElements collect: [ :each |
+			 each modelObjectFrom: aCollection ])
 ]
 
 { #category : 'rendering' }
diff --git a/repository/OpenPonk-Core/OPStonDiagramSerializer.class.st b/repository/OpenPonk-Core/OPStonDiagramSerializer.class.st
index bae45633..9128e152 100644
--- a/repository/OpenPonk-Core/OPStonDiagramSerializer.class.st
+++ b/repository/OpenPonk-Core/OPStonDiagramSerializer.class.st
@@ -24,28 +24,6 @@ OPStonDiagramSerializer class >> minImportVersion [
 	^ 1
 ]
 
-{ #category : 'serialize/materialize' }
-OPStonDiagramSerializer >> elementsByIdsFrom: elements [
-
-	SystemNotification signal: 'Elements: ' , elements size asString.
-	^ (elements withIndexCollect: [ :each :index |
-		   SystemNotification signal:
-			   'Processing E ' , index asString , ': ' , each asString.
-		   each uuid -> each.
-		   SystemNotification signal:
-			   'Processed E ' , index asString , ': ' , each asString ])
-		  asDictionary
-]
-
-{ #category : 'serialize/materialize' }
-OPStonDiagramSerializer >> elementsByIdsOf: aModel [
-
-	| innerElements allElements |
-	innerElements := OPNavigatorAdapters new allChildrenFor: aModel.
-	allElements := innerElements asArray copyWith: aModel.
-	^ self elementsByIdsFrom: allElements
-]
-
 { #category : 'accessing' }
 OPStonDiagramSerializer >> formatName [
 	^ 'ston'
@@ -54,9 +32,11 @@ OPStonDiagramSerializer >> formatName [
 { #category : 'serialize/materialize' }
 OPStonDiagramSerializer >> materializeDiagramOf: aModel from: aStream [
 
-	| diagram |
+	| diagram innerElements |
 	diagram := STON fromStream: aStream.
-	diagram resolveAllModelElements: (self elementsByIdsOf: aModel).
+	innerElements := OPNavigatorAdapters new allChildrenFor: aModel.
+	diagram resolveAllModelElements:
+		(innerElements asArray copyWith: aModel).
 	^ diagram
 ]