diff --git a/CHANGELOG.md b/CHANGELOG.md
index 826d9b9c..285c5a15 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,7 +1,9 @@
 # OHHTTPStubs — CHANGELOG
 
 ## Master
-
+* Fixed potential memory leaks with use of NSURLSession as detected by our devs.  
+  [@mikelupo](https://github.com/mikelupo
+  [#250](https://github.com/AliSoftware/OHHTTPStubs/pull/250)
 * Add precondition assertions in `isScheme` and `isHost` matchers and some documentation in `isHost`, `isScheme` and `isPath`.  
   [@Liquidsoul](https://github.com/Liquidsoul)
   [#248](https://github.com/AliSoftware/OHHTTPStubs/pull/248)
diff --git a/OHHTTPStubs/UnitTests/Test Suites/MocktailTests.m b/OHHTTPStubs/UnitTests/Test Suites/MocktailTests.m
index f43f4069..bda8b25e 100644
--- a/OHHTTPStubs/UnitTests/Test Suites/MocktailTests.m	
+++ b/OHHTTPStubs/UnitTests/Test Suites/MocktailTests.m	
@@ -53,6 +53,7 @@ - (void)setUp
 - (void)tearDown
 {
     [super tearDown];
+    [self.session invalidateAndCancel];
     self.session = nil;
 }
 
diff --git a/OHHTTPStubs/UnitTests/Test Suites/NSURLSessionTests.m b/OHHTTPStubs/UnitTests/Test Suites/NSURLSessionTests.m
index a5e95d30..77a2c2e3 100644
--- a/OHHTTPStubs/UnitTests/Test Suites/NSURLSessionTests.m	
+++ b/OHHTTPStubs/UnitTests/Test Suites/NSURLSessionTests.m	
@@ -195,6 +195,8 @@ - (void)test_SharedNSURLSession
             XCTAssertNil(redirectResponse, @"Unexpected redirect response received");
             XCTAssertEqualObjects(jsonResponse, json, @"Unexpected data received");
         }];
+
+        [session finishTasksAndInvalidate];
     }
     else
     {
@@ -220,6 +222,8 @@ - (void)test_NSURLSessionDefaultConfig
             XCTAssertNil(redirectResponse, @"Unexpected redirect response received");
             XCTAssertEqualObjects(jsonResponse, json, @"Unexpected data received");
         }];
+
+        [session finishTasksAndInvalidate];
     }
     else
     {
@@ -243,6 +247,8 @@ - (void)test_NSURLSessionDefaultConfig_notFollowingRedirects
             XCTAssertEqual(301, [redirectResponse statusCode], @"Expected 301 redirect");
             XCTAssertNil(jsonResponse, @"Unexpected data received");
         }];
+
+        [session finishTasksAndInvalidate];
     }
     else
     {
@@ -268,6 +274,8 @@ - (void)test_NSURLSessionEphemeralConfig
             XCTAssertNil(redirectResponse, @"Unexpected redirect response received");
             XCTAssertEqualObjects(jsonResponse, json, @"Unexpected data received");
         }];
+
+        [session finishTasksAndInvalidate];
     }
     else
     {
@@ -296,6 +304,8 @@ - (void)test_NSURLSessionDefaultConfig_Disabled
             XCTAssertNil(redirectResponse, @"Redirect response should not have been received as stubs should be disabled");
             XCTAssertNil(jsonResponse, @"Data should not have been received as stubs should be disabled");
         }];
+
+        [session finishTasksAndInvalidate];
     }
     else
     {
@@ -325,6 +335,8 @@ - (void)test_NSURLSession_DataTask_DelegateMethods
         [self waitForExpectationsWithTimeout:5 handler:nil];
         
         XCTAssertEqualObjects(_receivedData, expectedResponse, @"Unexpected response");
+
+        [session finishTasksAndInvalidate];
     }
     else
     {
@@ -370,6 +382,8 @@ - (void)test_NSURLSessionCustomHTTPBody
         [self waitForExpectationsWithTimeout:5 handler:nil];
 
         XCTAssertNil(_receivedData, @"Unexpected response: HTTP body check should not be successful");
+
+        [session finishTasksAndInvalidate];
     }
     else
     {
@@ -403,6 +417,8 @@ - (void)test_NSURLSessionNativeHTTPBody
 
         [self waitForExpectationsWithTimeout:5 handler:nil];
         XCTAssertNil(_receivedData, @"[request HTTPBody] is not expected to work. If this has been fixed, the OHHTTPStubs_HTTPBody can be removed.");
+
+        [session finishTasksAndInvalidate];
     }
     else
     {