diff --git a/FileBrowser.xcodeproj/project.pbxproj b/FileBrowser.xcodeproj/project.pbxproj
index b329c3f..72d2116 100644
--- a/FileBrowser.xcodeproj/project.pbxproj
+++ b/FileBrowser.xcodeproj/project.pbxproj
@@ -259,11 +259,11 @@
 				TargetAttributes = {
 					344169531C67812400B93D28 = {
 						CreatedOnToolsVersion = 7.2.1;
-						LastSwiftMigration = 0800;
+						LastSwiftMigration = 0900;
 					};
 					3441695D1C67812400B93D28 = {
 						CreatedOnToolsVersion = 7.2.1;
-						LastSwiftMigration = 0800;
+						LastSwiftMigration = 0900;
 						ProvisioningStyle = Manual;
 					};
 				};
@@ -463,7 +463,8 @@
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SKIP_INSTALL = YES;
 				SWIFT_OPTIMIZATION_LEVEL = "-Onone";
-				SWIFT_VERSION = 3.0;
+				SWIFT_SWIFT3_OBJC_INFERENCE = On;
+				SWIFT_VERSION = 4.0;
 			};
 			name = Debug;
 		};
@@ -482,7 +483,8 @@
 				PRODUCT_BUNDLE_IDENTIFIER = com.roymarmelstein.FileBrowser;
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SKIP_INSTALL = YES;
-				SWIFT_VERSION = 3.0;
+				SWIFT_SWIFT3_OBJC_INFERENCE = On;
+				SWIFT_VERSION = 4.0;
 			};
 			name = Release;
 		};
@@ -494,7 +496,8 @@
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks @loader_path/Frameworks";
 				PRODUCT_BUNDLE_IDENTIFIER = com.roymarmelstein.FileBrowserTests;
 				PRODUCT_NAME = "$(TARGET_NAME)";
-				SWIFT_VERSION = 3.0;
+				SWIFT_SWIFT3_OBJC_INFERENCE = On;
+				SWIFT_VERSION = 4.0;
 			};
 			name = Debug;
 		};
@@ -506,7 +509,8 @@
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks @loader_path/Frameworks";
 				PRODUCT_BUNDLE_IDENTIFIER = com.roymarmelstein.FileBrowserTests;
 				PRODUCT_NAME = "$(TARGET_NAME)";
-				SWIFT_VERSION = 3.0;
+				SWIFT_SWIFT3_OBJC_INFERENCE = On;
+				SWIFT_VERSION = 4.0;
 			};
 			name = Release;
 		};
diff --git a/FileBrowser/FileBrowser.swift b/FileBrowser/FileBrowser.swift
index a424d92..aad61e3 100644
--- a/FileBrowser/FileBrowser.swift
+++ b/FileBrowser/FileBrowser.swift
@@ -48,12 +48,14 @@ open class FileBrowser: UINavigationController {
     ///   - initialPath: NSURL filepath to containing directory.
     ///   - allowEditing: Whether to allow editing.
     ///   - showCancelButton: Whether to show the cancel button.
-    public convenience init(initialPath: URL = FileParser.sharedInstance.documentsURL(), allowEditing: Bool = false, showCancelButton: Bool = true) {
-        let fileListViewController = FileListViewController(initialPath: initialPath, showCancelButton: showCancelButton)
+    public convenience init(initialPath: URL? = nil, allowEditing: Bool = false, showCancelButton: Bool = true) {
+        
+        let validInitialPath = initialPath ?? FileParser.sharedInstance.documentsURL()
+        
+        let fileListViewController = FileListViewController(initialPath: validInitialPath, showCancelButton: showCancelButton)
         fileListViewController.allowEditing = allowEditing
         self.init(rootViewController: fileListViewController)
         self.view.backgroundColor = UIColor.white
         self.fileList = fileListViewController
     }
-    
 }
diff --git a/FileBrowser/WebviewPreviewViewContoller.swift b/FileBrowser/WebviewPreviewViewContoller.swift
index 0a4e43c..f1b40bc 100644
--- a/FileBrowser/WebviewPreviewViewContoller.swift
+++ b/FileBrowser/WebviewPreviewViewContoller.swift
@@ -39,7 +39,7 @@ class WebviewPreviewViewContoller: UIViewController {
     
     //MARK: Share
     
-    func shareFile(_ sender: UIBarButtonItem) {
+    @objc func shareFile(_ sender: UIBarButtonItem) {
         guard let file = file else {
             return
         }