diff --git a/Simplenote/NSView+Simplenote.swift b/Simplenote/NSView+Simplenote.swift
index b7cebdcb6..7d27fe74c 100644
--- a/Simplenote/NSView+Simplenote.swift
+++ b/Simplenote/NSView+Simplenote.swift
@@ -19,4 +19,10 @@ extension NSView {
         let effectiveResponder = fieldEditor?.delegate as? NSControl
         return effectiveResponder == self
     }
+
+    /// Returns first layout constraint found for attribute type
+    ///
+    func firstContraint(firstView: NSView, firstAttribute: NSLayoutConstraint.Attribute) -> NSLayoutConstraint? {
+        constraints.first(where: { $0.firstItem as? NSView == firstView && $0.firstAttribute == firstAttribute })
+    }
 }
diff --git a/Simplenote/SPNavigationController.swift b/Simplenote/SPNavigationController.swift
index fdb8667bc..221ee3001 100644
--- a/Simplenote/SPNavigationController.swift
+++ b/Simplenote/SPNavigationController.swift
@@ -160,8 +160,8 @@ class SPNavigationController: NSViewController {
     }
 
     private func animateTransition(slidingView: NSView, fadingView: NSView?, direction: AnimationDirection, onCompletion: @escaping () -> Void) {
-        guard let leadingConstraint = view.constraints.first(where: { $0.firstItem as? NSView == slidingView && $0.firstAttribute == .leading }),
-              let trailingConstraint = view.constraints.first(where: { $0.firstItem as? NSView == slidingView && $0.firstAttribute == .trailing }) else {
+        guard let leadingConstraint = view.firstContraint(firstView: slidingView, firstAttribute: .leading),
+              let trailingConstraint = view.firstContraint(firstView: slidingView, firstAttribute: .trailing) else {
             return
         }