diff --git a/MVMCoreUI/Atomic/MoleculeObjectMapping.swift b/MVMCoreUI/Atomic/MoleculeObjectMapping.swift
index ce86fc26..4f151642 100644
--- a/MVMCoreUI/Atomic/MoleculeObjectMapping.swift
+++ b/MVMCoreUI/Atomic/MoleculeObjectMapping.swift
@@ -34,6 +34,18 @@ import Foundation
         return type.init(model: model, delegateObject, additionalData)
     }
     
+    /// Convenience function for legacy classes
+    public func getMoleculeModelForJSON(_ json: [String: Any]) throws -> MoleculeModelProtocol? {
+        guard let moleculeName = json.optionalStringForKey(KeyMoleculeName),
+            let type = ModelRegistry.getType(for: moleculeName, with: MoleculeModelProtocol.self) else {
+            throw ModelRegistry.Error.decoderErrorModelNotMapped
+        }
+        guard let model = try type.decode(jsonDict: json) as? MoleculeModelProtocol else {
+            throw ModelRegistry.Error.decoderError
+        }
+        return model
+    }
+    
     /// Call to register all of the CoreUI molecules.
     public static func registerObjects() {
         // Stacks
diff --git a/MVMCoreUI/Containers/NavigationController.swift b/MVMCoreUI/Containers/NavigationController.swift
index 8e7279ce..0d4d0a56 100644
--- a/MVMCoreUI/Containers/NavigationController.swift
+++ b/MVMCoreUI/Containers/NavigationController.swift
@@ -93,10 +93,7 @@ import UIKit
     
     /// Convenience setter for legacy files
     public static func set(navigationController: UINavigationController, navigationJSON: [String: Any], viewController: UIViewController) throws {
-        guard let moleculeName = ModelRegistry.getType(for: navigationJSON.stringForkey(KeyMoleculeName), with: MoleculeModelProtocol.self) else {
-            throw ModelRegistry.Error.keyNotFound
-        }
-        guard let barModel = try moleculeName.decode(jsonDict: navigationJSON) as? (MoleculeModelProtocol & NavigationItemModelProtocol) else {
+        guard let barModel = try MoleculeObjectMapping.shared()?.getMoleculeModelForJSON(navigationJSON) as? (MoleculeModelProtocol & NavigationItemModelProtocol) else {
             throw ModelRegistry.Error.decoderOther(message: "Model not a bar model")
         }
         set(navigationController: navigationController, navigationItemModel: barModel, viewController: viewController)