diff --git a/cull/CullApp.swift b/cull/CullApp.swift
index 4dd8881..3c30d4a 100644
--- a/cull/CullApp.swift
+++ b/cull/CullApp.swift
@@ -86,8 +86,7 @@ struct CullApp: App {
                 Divider()
 
                 Button("Close Folder") {
-                    session.sourceFolder = nil
-                    session.groups = []
+                    session.closeSourceFolder()
                     thumbnailCache.clearCache()
                 }
                 .keyboardShortcut("w")
diff --git a/cull/Models/CullSession.swift b/cull/Models/CullSession.swift
index 8ba8e5a..5e6bfa2 100644
--- a/cull/Models/CullSession.swift
+++ b/cull/Models/CullSession.swift
@@ -8,7 +8,17 @@ final class CullSession {
         get { UserDefaults.standard.object(forKey: "autoWriteXMP") as? Bool ?? true }
         set { UserDefaults.standard.set(newValue, forKey: "autoWriteXMP") }
     }
-    var sourceFolder: URL?
+    var sourceFolder: URL? {
+        didSet {
+            // Stop access on old folder
+            if let oldValue, sourceFolderAccessActive {
+                oldValue.stopAccessingSecurityScopedResource()
+                sourceFolderAccessActive = false
+            }
+        }
+    }
+    /// Whether we currently hold security-scoped access on sourceFolder
+    private var sourceFolderAccessActive = false
     var groups: [PhotoGroup] = []
     var selectedGroupIndex: Int = 0
     var selectedPhotoIndex: Int = 0
@@ -316,6 +326,25 @@ final class CullSession {
         zoomFaceIndex = nil
     }
 
+    // MARK: - Security-scoped folder access
+
+    /// Open a folder with security-scoped access. Call this instead of setting sourceFolder directly.
+    func openSourceFolder(_ url: URL) {
+        _ = url.startAccessingSecurityScopedResource()
+        sourceFolderAccessActive = true
+        sourceFolder = url
+    }
+
+    /// Close the current folder, releasing security-scoped access.
+    func closeSourceFolder() {
+        if let folder = sourceFolder, sourceFolderAccessActive {
+            folder.stopAccessingSecurityScopedResource()
+            sourceFolderAccessActive = false
+        }
+        sourceFolder = nil
+        groups = []
+    }
+
     // MARK: - Workspace persistence
 
     /// Debounced auto-save — coalesces rapid changes into a single write
diff --git a/cull/Views/ContentView.swift b/cull/Views/ContentView.swift
index 4fa892b..8543e20 100644
--- a/cull/Views/ContentView.swift
+++ b/cull/Views/ContentView.swift
@@ -22,7 +22,7 @@ struct ContentView: View {
                     Text("No supported photos found")
                         .font(.title3)
                         .foregroundStyle(.secondary)
-                    Button("Choose Another Folder") { session.sourceFolder = nil }
+                    Button("Choose Another Folder") { session.closeSourceFolder() }
                 }
                 .frame(maxWidth: .infinity, maxHeight: .infinity)
             } else {
@@ -48,7 +48,7 @@ struct ContentView: View {
 
     @MainActor
     private func startImport(_ url: URL) {
-        session.sourceFolder = url
+        session.openSourceFolder(url)
         session.isImporting = true
         session.importProgress = 0.02
         cache.clearCache()
@@ -227,7 +227,7 @@ struct ContentView: View {
                 }
             } catch {
                 await MainActor.run {
-                    s.sourceFolder = nil
+                    s.closeSourceFolder()
                     s.isImporting = false
                 }
             }
@@ -470,7 +470,7 @@ struct ContentView: View {
             }
 
             ToolbarItem(placement: .automatic) {
-                Button { session.sourceFolder = nil } label: {
+                Button { session.closeSourceFolder() } label: {
                     Image(systemName: "folder")
                 }
                 .help("Open Folder")
diff --git a/cull/Views/ExportSheet.swift b/cull/Views/ExportSheet.swift
index 6be25ce..41f0107 100644
--- a/cull/Views/ExportSheet.swift
+++ b/cull/Views/ExportSheet.swift
@@ -121,12 +121,11 @@ struct ExportSheet: View {
         let sourceFolder = session.sourceFolder
 
         Task {
-            // Access security-scoped resources
+            // Access security-scoped resource for destination
+            // (source folder access is held by CullSession for its lifetime)
             let destAccess = destination.startAccessingSecurityScopedResource()
-            let srcAccess = sourceFolder?.startAccessingSecurityScopedResource() ?? false
             defer {
                 if destAccess { destination.stopAccessingSecurityScopedResource() }
-                if srcAccess { sourceFolder?.stopAccessingSecurityScopedResource() }
             }
 
             let exportResult = await PhotoExporter.export(