diff --git a/Cartfile b/Cartfile
index 62674f6..c05eee3 100644
--- a/Cartfile
+++ b/Cartfile
@@ -1,3 +1,5 @@
-github "mxcl/PromiseKit" ~> 6.3
+#github "mxcl/PromiseKit" ~> 6.3
+github "dougzilla32/PromiseKit" "CoreCancel"
 github "mxcl/OMGHTTPURLRQ" ~> 3.2
-github "PromiseKit/Foundation" ~> 3.1
+#github "PromiseKit/Foundation" ~> 3.1
+github "dougzilla32/Foundation" "CoreCancel"
diff --git a/Cartfile.resolved b/Cartfile.resolved
index ebbdb14..afccdca 100644
--- a/Cartfile.resolved
+++ b/Cartfile.resolved
@@ -1,4 +1,4 @@
 github "AliSoftware/OHHTTPStubs" "6.1.0"
-github "PromiseKit/Foundation" "3.1.0"
+github "dougzilla32/Foundation" "4b6d86210cf2f3a2010d37c44d7d63ccb20547b1"
+github "dougzilla32/PromiseKit" "288f7fbabc0b33c558bf908a3a0770693223d4e0"
 github "mxcl/OMGHTTPURLRQ" "3.2.5"
-github "mxcl/PromiseKit" "6.3.3"
diff --git a/Sources/NSURLSession+OMG+Promise.swift b/Sources/NSURLSession+OMG+Promise.swift
index eca8512..0e4b921 100644
--- a/Sources/NSURLSession+OMG+Promise.swift
+++ b/Sources/NSURLSession+OMG+Promise.swift
@@ -168,3 +168,141 @@ extension URLSession {
         }
     }
 }
+
+//////////////////////////////////////////////////////////// Cancellable wrappers
+
+extension URLSession {
+    /**
+     Makes a cancellable **GET** request to the provided URL.
+
+         let p = URLSession.shared.GET("http://example.com", query: ["foo": "bar"])
+         p.then { data -> Void  in
+             //…
+         }
+         p.asImage().then { image -> Void  in
+            //…
+         }
+         p.asDictionary().then { json -> Void  in
+            //…
+         }
+
+     - Parameter url: The URL to request.
+     - Parameter query: The parameters to be encoded as the query string for the GET request.
+     - Returns: A cancellable promise that represents the GET request.
+     */
+    public func cancellableGET(_ url: String, query: [String: Any]? = nil) -> CancellablePromise<(data: Data, response: URLResponse)> {
+        return cancellable(GET(url, query: query))
+    }
+
+    /**
+     Makes a cancellable POST request to the provided URL passing form URL encoded
+     parameters.
+
+     Form URL-encoding is the standard way to POST on the Internet, so
+     probably this is what you want. If it doesn’t work, try the `+POST:JSON`
+     variant.
+
+         let url = "http://jsonplaceholder.typicode.com/posts"
+         let params = ["title": "foo", "body": "bar", "userId": 1]
+         URLSession.shared.POST(url, formData: params).asDictionary().then { json -> Void  in
+             //…
+         }
+
+     - Parameter url: The URL to request.
+     - Parameter formData: The parameters to be form URL-encoded and passed as the POST body.
+     - Returns: A cancellable promise that represents the POST request.
+     */
+    public func cancellablePOST(_ url: String, formData: [String: Any]? = nil) -> CancellablePromise<(data: Data, response: URLResponse)> {
+        return cancellable(POST(url, formData: formData))
+    }
+
+    /**
+     Makes a cancellable POST request to the provided URL passing multipart form-data.
+
+        let formData = OMGMultipartFormData()
+        let imgData = Data(contentsOfFile: "image.png")
+        formData.addFile(imgdata, parameterName: "file1", filename: "myimage1.png", contentType: "image/png")
+
+        URLSession.shared.POST(url, multipartFormData: formData).then { data in
+            //…
+        }
+
+     - Parameter url: The URL to request.
+     - Parameter multipartFormData: The parameters to be multipart form-data encoded and passed as the POST body.
+     - Returns: A cancellable promise that represents the POST request.
+     - SeeAlso: [https://github.com/mxcl/OMGHTTPURLRQ](OMGHTTPURLRQ)
+     */
+    public func cancellablePOST(_ url: String, multipartFormData: OMGMultipartFormData) -> CancellablePromise<(data: Data, response: URLResponse)> {
+        return cancellable(POST(url, multipartFormData: multipartFormData))
+    }
+
+    /**
+     Makes a cancellable POST request to the provided URL passing JSON encoded
+     parameters.
+
+     Most web servers nowadays support POST with either JSON or form
+     URL-encoding. If in doubt try form URL-encoded parameters first.
+
+         let url = "http://jsonplaceholder.typicode.com/posts"
+         let params = ["title": "foo", "body": "bar", "userId": 1]
+         URLSession.shared.POST(url, json: params).asDictionary().then { json -> Void  in
+             //…
+         }
+
+     - Parameter url: The URL to request.
+     - Parameter json: The parameters to be JSON-encoded and passed as the POST body.
+     - Returns: A cancellable promise that represents the POST request.
+     */
+    public func cancellablePOST(_ url: String, json: [String: Any]? = nil) -> CancellablePromise<(data: Data, response: URLResponse)> {
+        return cancellable(POST(url, json: json))
+    }
+
+    /**
+     Makes a cancellable PUT request to the provided URL passing JSON encoded parameters.
+
+         let url = "http://jsonplaceholder.typicode.com/posts"
+         let params = ["title": "foo", "body": "bar", "userId": 1]
+         URLSession.shared.PUT(url, json: params).asDictionary().then { json -> Void  in
+             //…
+         }
+
+     - Parameter url: The URL to request.
+     - Parameter json: The parameters to be JSON-encoded and passed as the PUT body.
+     - Returns: A cancellable promise that represents the PUT request.
+     */
+    public func cancellablePUT(_ url: String, json: [String: Any]? = nil) -> CancellablePromise<(data: Data, response: URLResponse)> {
+        return cancellable(PUT(url, json: json))
+    }
+
+    /**
+     Makes a cancellable DELETE request to the provided URL passing form URL-encoded
+     parameters.
+
+         let url = "http://jsonplaceholder.typicode.com/posts/1"
+         URLSession.shared.DELETE(url).then.asDictionary() { json -> Void in
+             //…
+         }
+
+     - Parameter url: The URL to request.
+     - Returns: A cancellable promise that represents the PUT request.
+     */
+    public func cancellableDELETE(_ url: String) -> CancellablePromise<(data: Data, response: URLResponse)> {
+        return cancellable(DELETE(url))
+    }
+
+    /**
+     Makes a cancellable PATCH request to the provided URL passing the provided JSON parameters.
+
+         let url = "http://jsonplaceholder.typicode.com/posts/1"
+         let params = ["foo": "bar"]
+         NSURLConnection.PATCH(url, json: params).asDictionary().then { json -> Void in
+             //…
+         }
+     - Parameter url: The URL to request.
+     - Parameter json: The JSON parameters to encode as the PATCH body.
+     - Returns: A cancellable promise that represents the PUT request.
+     */
+    public func cancellablePATCH(_ url: String, json: [String: Any]? = nil) -> CancellablePromise<(data: Data, response: URLResponse)> {
+        return cancellable(PATCH(url, json: json))
+    }
+}
diff --git a/Tests/TestNSURLSession.swift b/Tests/TestNSURLSession.swift
index 8e3d77e..f9a60ac 100644
--- a/Tests/TestNSURLSession.swift
+++ b/Tests/TestNSURLSession.swift
@@ -72,3 +72,81 @@ class NSURLSessionTests: XCTestCase {
         OHHTTPStubs.removeAllStubs()
     }
 }
+
+//////////////////////////////////////////////////////////// Cancellation
+
+extension NSURLSessionTests {
+    func testCancel1() {
+        let json: NSDictionary = ["key1": "value1", "key2": ["value2A", "value2B"]]
+
+        OHHTTPStubs.stubRequests(passingTest: { $0.url!.host == "example.com" }) { _ in
+            return OHHTTPStubsResponse(jsonObject: json, statusCode: 200, headers: nil)
+        }
+
+        let ex = expectation(description: "")
+        URLSession.shared.cancellableGET("http://example.com").compactMap {
+            XCTFail()
+            try JSONSerialization.jsonObject(with: $0.data)
+        }.done {
+            XCTAssertEqual(json, $0 as? NSDictionary)
+            XCTFail()
+        }.catch(policy: .allErrors) {
+            $0.isCancelled ? ex.fulfill() : XCTFail()
+        }.cancel()
+        waitForExpectations(timeout: 1)
+    }
+
+    func testCancel2() {
+
+        // test that Promise<Data> chains thens
+        // this test because I don’t trust the Swift compiler
+
+        let dummy = ("fred" as NSString).data(using: String.Encoding.utf8.rawValue)!
+
+        OHHTTPStubs.stubRequests(passingTest: { $0.url!.host == "example.com" }) { _ in
+            return OHHTTPStubsResponse(data: dummy, statusCode: 200, headers: [:])
+        }
+
+        let ex = expectation(description: "")
+
+        cancellable(after(seconds: 0.1)).then { () -> CancellablePromise<(data: Data, response: URLResponse)> in
+            let p = URLSession.shared.cancellableGET("http://example.com")
+            p.cancel()
+            return p
+        }.done {
+            XCTAssertEqual($0.data, dummy)
+            XCTFail()
+        }.catch(policy: .allErrors) {
+            $0.isCancelled ? ex.fulfill() : XCTFail()
+        }
+
+        waitForExpectations(timeout: 1)
+    }
+
+    func testCancelSyntax() {
+        let json: NSDictionary = ["key1": "value1", "key2": ["value2A", "value2B"]]
+
+        OHHTTPStubs.stubRequests(passingTest: {
+            $0.url!.host == "example.com"
+        }, withStubResponse: { _ in
+            OHHTTPStubsResponse(jsonObject: json, statusCode: 200, headers: nil)
+        })
+
+        let p = URLSession.shared.cancellableGET("http://example.com", query: [
+            "1": 1,
+            "2": 2
+        ])
+
+        let ex = expectation(description: "")
+        p.compactMap {
+            p.cancel()
+            try JSONSerialization.jsonObject(with: $0.data)
+        }.done {
+            XCTAssertEqual(json, $0 as? NSDictionary)
+            XCTFail()
+        }.catch(policy: .allErrors) {
+            $0.isCancelled ? ex.fulfill() : XCTFail()
+        }
+        waitForExpectations(timeout: 1)
+    }
+}