diff --git a/Sources/SwiftKit/Coding/Base64StringCoder.swift b/Sources/SwiftKit/Coding/Base64StringCoder.swift
index fb2b1fa..f095f6c 100644
--- a/Sources/SwiftKit/Coding/Base64StringCoder.swift
+++ b/Sources/SwiftKit/Coding/Base64StringCoder.swift
@@ -18,7 +18,7 @@ public class Base64StringCoder: StringCoder {
     /**
      Decode a base64 encoded string.
      */
-    public func decode(string: String) -> String? {
+    public func decode(_ string: String) -> String? {
         guard let data = Data(base64Encoded: string, options: .ignoreUnknownCharacters) else { return nil }
         return String(data: data, encoding: .utf8)
     }
@@ -26,7 +26,7 @@ public class Base64StringCoder: StringCoder {
     /**
      Encode a string to base64.
     */
-    public func encode(string: String) -> String? {
+    public func encode(_ string: String) -> String? {
         let data = string.data(using: .utf8)
         let encoded = data?.base64EncodedData(options: .endLineWithLineFeed)
         guard let encodedData = encoded else { return nil }
diff --git a/Sources/SwiftKit/Coding/StringDecoder.swift b/Sources/SwiftKit/Coding/StringDecoder.swift
index 72b4b14..408649b 100644
--- a/Sources/SwiftKit/Coding/StringDecoder.swift
+++ b/Sources/SwiftKit/Coding/StringDecoder.swift
@@ -14,5 +14,5 @@ import Foundation
  */
 public protocol StringDecoder: AnyObject {
     
-    func decode(string: String) -> String?
+    func decode(_ string: String) -> String?
 }
diff --git a/Sources/SwiftKit/Coding/StringEncoder.swift b/Sources/SwiftKit/Coding/StringEncoder.swift
index 609c5e7..0e799aa 100644
--- a/Sources/SwiftKit/Coding/StringEncoder.swift
+++ b/Sources/SwiftKit/Coding/StringEncoder.swift
@@ -14,5 +14,5 @@ import Foundation
  */
 public protocol StringEncoder: AnyObject {
    
-    func encode(string: String) -> String?
+    func encode(_ string: String) -> String?
 }
diff --git a/SwiftKitDemo/SwiftKitDemo.xcodeproj/project.xcworkspace/xcuserdata/danielsaidi.xcuserdatad/UserInterfaceState.xcuserstate b/SwiftKitDemo/SwiftKitDemo.xcodeproj/project.xcworkspace/xcuserdata/danielsaidi.xcuserdatad/UserInterfaceState.xcuserstate
index 07c1cd3..2594999 100644
Binary files a/SwiftKitDemo/SwiftKitDemo.xcodeproj/project.xcworkspace/xcuserdata/danielsaidi.xcuserdatad/UserInterfaceState.xcuserstate and b/SwiftKitDemo/SwiftKitDemo.xcodeproj/project.xcworkspace/xcuserdata/danielsaidi.xcuserdatad/UserInterfaceState.xcuserstate differ
diff --git a/SwiftKitDemo/SwiftKitDemo/Screens/CodingScreen.swift b/SwiftKitDemo/SwiftKitDemo/Screens/CodingScreen.swift
index 2343ec3..1713a36 100644
--- a/SwiftKitDemo/SwiftKitDemo/Screens/CodingScreen.swift
+++ b/SwiftKitDemo/SwiftKitDemo/Screens/CodingScreen.swift
@@ -48,13 +48,13 @@ extension CodingScreen {
     
     func base64Decode() {
         let string = coder.encode(string: "This is a string")!
-        let result = coder.decode(string: string)!
+        let result = coder.decode(string)!
         resultText = "\"\(string)\" was decoded to \"\(result)\""
     }
     
     func base64Encode() {
         let string = "This is a string"
-        let result = coder.encode(string: string)!
+        let result = coder.encode(string)!
         resultText = "\"\(string)\" was encoded to \"\(result)\""
     }
 }
diff --git a/Tests/SwiftKitTests/Coding/Base64StringCoderTests.swift b/Tests/SwiftKitTests/Coding/Base64StringCoderTests.swift
index 5a57e4d..a6e34bf 100644
--- a/Tests/SwiftKitTests/Coding/Base64StringCoderTests.swift
+++ b/Tests/SwiftKitTests/Coding/Base64StringCoderTests.swift
@@ -27,7 +27,7 @@ class Base64StringEncoderTests: QuickSpec {
 foo
 bar
 """
-                let encoded = coder.encode(string: string)
+                let encoded = coder.encode(string)
                 expect(encoded).to(equal("Zm9vCmJhcg=="))
             }
         }
@@ -36,7 +36,7 @@ bar
             
             it("fails for non-encoded string") {
                 let string = "test"
-                let decoded = coder.decode(string: string)
+                let decoded = coder.decode(string)
                 expect(decoded).to(beNil())
             }
             
@@ -45,8 +45,8 @@ bar
 foo
 bar
 """
-                let encoded = coder.encode(string: string)!
-                let decoded = coder.decode(string: encoded)
+                let encoded = coder.encode(string)!
+                let decoded = coder.decode(encoded)
                 expect(decoded).to(equal(string))
             }
         }