diff --git a/RxSwift/Observables/Implementations/Debug.swift b/RxSwift/Observables/Implementations/Debug.swift
index 2b2d3e92..c92c9a28 100644
--- a/RxSwift/Observables/Implementations/Debug.swift
+++ b/RxSwift/Observables/Implementations/Debug.swift
@@ -52,7 +52,7 @@ class Debug<Element> : Producer<Element> {
     
     private let _source: Observable<Element>
 
-    init(source: Observable<Element>, identifier: String?, file: String, line: Int, function: String) {
+    init(source: Observable<Element>, identifier: String?, file: String, line: UInt, function: String) {
         if let identifier = identifier {
             _identifier = identifier
         }
diff --git a/RxSwift/Observables/Observable+Debug.swift b/RxSwift/Observables/Observable+Debug.swift
index c40e9c6e..41da70aa 100644
--- a/RxSwift/Observables/Observable+Debug.swift
+++ b/RxSwift/Observables/Observable+Debug.swift
@@ -21,7 +21,7 @@ extension ObservableType {
     - returns: An observable sequence whose events are printed to standard output.
     */
     @warn_unused_result(message="http://git.io/rxs.uo")
-    public func debug(identifier: String? = nil, file: String = __FILE__, line: Int = __LINE__, function: String = __FUNCTION__)
+    public func debug(identifier: String? = nil, file: String = __FILE__, line: UInt = __LINE__, function: String = __FUNCTION__)
         -> Observable<E> {
         return Debug(source: self.asObservable(), identifier: identifier, file: file, line: line, function: function)
     }