diff --git a/FSPagerView/FSPagerView.xcodeproj/project.pbxproj b/FSPagerView/FSPagerView.xcodeproj/project.pbxproj
index e1df11f..323fc65 100644
--- a/FSPagerView/FSPagerView.xcodeproj/project.pbxproj
+++ b/FSPagerView/FSPagerView.xcodeproj/project.pbxproj
@@ -302,7 +302,7 @@
 				PRODUCT_BUNDLE_IDENTIFIER = com.wenchaod.FSPagerView;
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SKIP_INSTALL = YES;
-				SWIFT_VERSION = 3.0;
+				SWIFT_VERSION = 4.0;
 			};
 			name = Debug;
 		};
@@ -322,7 +322,7 @@
 				PRODUCT_BUNDLE_IDENTIFIER = com.wenchaod.FSPagerView;
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SKIP_INSTALL = YES;
-				SWIFT_VERSION = 3.0;
+				SWIFT_VERSION = 4.0;
 			};
 			name = Release;
 		};
diff --git a/FSPagerViewExample-Objc/FSPagerViewExample-Objc.xcodeproj/project.pbxproj b/FSPagerViewExample-Objc/FSPagerViewExample-Objc.xcodeproj/project.pbxproj
index 91b15e8..6aa7c4c 100644
--- a/FSPagerViewExample-Objc/FSPagerViewExample-Objc.xcodeproj/project.pbxproj
+++ b/FSPagerViewExample-Objc/FSPagerViewExample-Objc.xcodeproj/project.pbxproj
@@ -257,12 +257,14 @@
 					F9C694481E40C6C1007084B6 = {
 						CreatedOnToolsVersion = 8.2.1;
 						DevelopmentTeam = HZF422TY46;
+						LastSwiftMigration = 0900;
 						ProvisioningStyle = Automatic;
 						TestTargetID = F9EC37181E304A830022B6D6;
 					};
 					F9EC37181E304A830022B6D6 = {
 						CreatedOnToolsVersion = 8.2.1;
 						DevelopmentTeam = HZF422TY46;
+						LastSwiftMigration = 0900;
 						ProvisioningStyle = Automatic;
 					};
 				};
@@ -384,7 +386,8 @@
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SWIFT_ACTIVE_COMPILATION_CONDITIONS = DEBUG;
 				SWIFT_OPTIMIZATION_LEVEL = "-Onone";
-				SWIFT_VERSION = 3.0;
+				SWIFT_SWIFT3_OBJC_INFERENCE = On;
+				SWIFT_VERSION = 4.0;
 				TEST_TARGET_NAME = "FSPagerViewExample-Objc";
 			};
 			name = Debug;
@@ -400,7 +403,8 @@
 				PRODUCT_BUNDLE_IDENTIFIER = "com.wenchaod.FSPagerViewExample-ObjcUITests";
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SWIFT_OPTIMIZATION_LEVEL = "-Owholemodule";
-				SWIFT_VERSION = 3.0;
+				SWIFT_SWIFT3_OBJC_INFERENCE = On;
+				SWIFT_VERSION = 4.0;
 				TEST_TARGET_NAME = "FSPagerViewExample-Objc";
 			};
 			name = Release;
@@ -517,7 +521,8 @@
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks";
 				PRODUCT_BUNDLE_IDENTIFIER = "com.wenchaod.FSPagerView-Objc";
 				PRODUCT_NAME = "$(TARGET_NAME)";
-				SWIFT_VERSION = 3.0;
+				SWIFT_SWIFT3_OBJC_INFERENCE = Default;
+				SWIFT_VERSION = 4.0;
 			};
 			name = Debug;
 		};
@@ -530,7 +535,8 @@
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks";
 				PRODUCT_BUNDLE_IDENTIFIER = "com.wenchaod.FSPagerView-Objc";
 				PRODUCT_NAME = "$(TARGET_NAME)";
-				SWIFT_VERSION = 3.0;
+				SWIFT_SWIFT3_OBJC_INFERENCE = Default;
+				SWIFT_VERSION = 4.0;
 			};
 			name = Release;
 		};
diff --git a/Sources/FSPageViewTransformer.swift b/Sources/FSPageViewTransformer.swift
index 8a77c86..2878679 100644
--- a/Sources/FSPageViewTransformer.swift
+++ b/Sources/FSPageViewTransformer.swift
@@ -29,6 +29,7 @@ open class FSPagerViewTransformer: NSObject {
     open var minimumScale: CGFloat = 0.65
     open var minimumAlpha: CGFloat = 0.6
     
+    @objc
     public init(type: FSPagerViewTransformerType) {
         self.type = type
         switch type {
diff --git a/Sources/FSPagerView.swift b/Sources/FSPagerView.swift
index 2be9eca..6e3af53 100644
--- a/Sources/FSPagerView.swift
+++ b/Sources/FSPagerView.swift
@@ -162,6 +162,7 @@ open class FSPagerView: UIView,UICollectionViewDataSource,UICollectionViewDelega
     }
     
     /// The transformer of the pager view.
+    @objc
     open var transformer: FSPagerViewTransformer? {
         didSet {
             self.transformer?.pagerView = self
diff --git a/Sources/FSPagerViewCell.swift b/Sources/FSPagerViewCell.swift
index ea862d3..286eb38 100644
--- a/Sources/FSPagerViewCell.swift
+++ b/Sources/FSPagerViewCell.swift
@@ -11,6 +11,7 @@ import UIKit
 open class FSPagerViewCell: UICollectionViewCell {
     
     /// Returns the label used for the main textual content of the pager view cell.
+    @objc
     open var textLabel: UILabel? {
         if let _ = _textLabel {
             return _textLabel
@@ -32,6 +33,7 @@ open class FSPagerViewCell: UICollectionViewCell {
     }
     
     /// Returns the image view of the pager view cell. Default is nil.
+    @objc
     open var imageView: UIImageView? {
         if let _ = _imageView {
             return _imageView