diff --git a/Heimdallr.xcodeproj/project.pbxproj b/Heimdallr.xcodeproj/project.pbxproj
index e541702..56b81d4 100644
--- a/Heimdallr.xcodeproj/project.pbxproj
+++ b/Heimdallr.xcodeproj/project.pbxproj
@@ -129,6 +129,8 @@
 		E258A16C1CC6BC8600649F5A /* OAuthAccessTokenDefaultParser.swift in Sources */ = {isa = PBXBuildFile; fileRef = E258A1651CC6B66900649F5A /* OAuthAccessTokenDefaultParser.swift */; };
 		E258A16D1CC6BC8700649F5A /* OAuthAccessTokenDefaultParser.swift in Sources */ = {isa = PBXBuildFile; fileRef = E258A1651CC6B66900649F5A /* OAuthAccessTokenDefaultParser.swift */; };
 		E258A16E1CC6BC8800649F5A /* OAuthAccessTokenDefaultParser.swift in Sources */ = {isa = PBXBuildFile; fileRef = E258A1651CC6B66900649F5A /* OAuthAccessTokenDefaultParser.swift */; };
+		E2A5A5031CF4D46A0087840B /* request-valid-norefresh.json in Resources */ = {isa = PBXBuildFile; fileRef = E2A5A5011CF4D4620087840B /* request-valid-norefresh.json */; };
+		E2A5A5041CF4D46B0087840B /* request-valid-norefresh.json in Resources */ = {isa = PBXBuildFile; fileRef = E2A5A5011CF4D4620087840B /* request-valid-norefresh.json */; };
 /* End PBXBuildFile section */
 
 /* Begin PBXContainerItemProxy section */
@@ -237,6 +239,7 @@
 		DC712A5E1C85AD77009860A5 /* watchOS-StaticLibrary.xcconfig */ = {isa = PBXFileReference; lastKnownFileType = text.xcconfig; path = "watchOS-StaticLibrary.xcconfig"; sourceTree = "<group>"; };
 		E258A1651CC6B66900649F5A /* OAuthAccessTokenDefaultParser.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = OAuthAccessTokenDefaultParser.swift; sourceTree = "<group>"; };
 		E258A1671CC6B8C500649F5A /* OAuthAccessTokenParser.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = OAuthAccessTokenParser.swift; sourceTree = "<group>"; };
+		E2A5A5011CF4D4620087840B /* request-valid-norefresh.json */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = text.json; path = "request-valid-norefresh.json"; sourceTree = "<group>"; };
 /* End PBXFileReference section */
 
 /* Begin PBXFrameworksBuildPhase section */
@@ -438,6 +441,7 @@
 				DC5220AD1BEA32A000F37F2A /* authorize-valid.json */,
 				DC5220AE1BEA32A000F37F2A /* request-invalid-norefresh.json */,
 				DC5220AF1BEA32A000F37F2A /* request-invalid.json */,
+				E2A5A5011CF4D4620087840B /* request-valid-norefresh.json */,
 				DC5220B01BEA32A000F37F2A /* request-valid.json */,
 			);
 			path = "JSON Responses";
@@ -813,6 +817,7 @@
 			isa = PBXResourcesBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
+				E2A5A5041CF4D46B0087840B /* request-valid-norefresh.json in Resources */,
 				DC5220BF1BEA32A000F37F2A /* request-valid.json in Resources */,
 				DC5220B11BEA32A000F37F2A /* authorize-error.json in Resources */,
 				DC5220B71BEA32A000F37F2A /* authorize-invalid.json in Resources */,
@@ -835,6 +840,7 @@
 			isa = PBXResourcesBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
+				E2A5A5031CF4D46A0087840B /* request-valid-norefresh.json in Resources */,
 				DC5220C01BEA32A000F37F2A /* request-valid.json in Resources */,
 				DC5220B21BEA32A000F37F2A /* authorize-error.json in Resources */,
 				DC5220B81BEA32A000F37F2A /* authorize-invalid.json in Resources */,
diff --git a/Heimdallr/Core/Heimdallr.swift b/Heimdallr/Core/Heimdallr.swift
index ef7cddd..5a01001 100644
--- a/Heimdallr/Core/Heimdallr.swift
+++ b/Heimdallr/Core/Heimdallr.swift
@@ -20,9 +20,6 @@ public let HeimdallrErrorNotAuthorized = 2
         get {
             return accessTokenStore.retrieveAccessToken()
         }
-        set {
-            accessTokenStore.storeAccessToken(newValue)
-        }
     }
     private let accessTokenParser: OAuthAccessTokenParser
     private let httpClient: HeimdallrHTTPClient
@@ -76,7 +73,7 @@ public let HeimdallrErrorNotAuthorized = 2
     /// **Note:** Sets the access token's expiration date to
     ///     1 January 1970, GMT.
     public func invalidateAccessToken() {
-        accessToken = accessToken?.copy(expiresAt: NSDate(timeIntervalSince1970: 0))
+        accessTokenStore.storeAccessToken(accessToken?.copy(expiresAt: NSDate(timeIntervalSince1970: 0)))
     }
 
     /// Clears the currently stored access token, if any.
@@ -143,8 +140,8 @@ public let HeimdallrErrorNotAuthorized = 2
             } else if (response as! NSHTTPURLResponse).statusCode == 200 {
                 switch self.accessTokenParser.parse(data!) {
                 case let .Success(accessToken):
-                    self.accessToken = accessToken
-                    completion(.Success(accessToken))
+                    let updatedAccessToken = self.updateAccessToken(accessToken)
+                    completion(.Success(updatedAccessToken))
                 default:
                     let userInfo = [
                         NSLocalizedDescriptionKey: NSLocalizedString("Could not authorize grant", comment: ""),
@@ -170,6 +167,24 @@ public let HeimdallrErrorNotAuthorized = 2
             }
         }
     }
+    
+    /// Updates the stored access token with a new one.
+    ///
+    /// - parameter accessToken: The new access token.
+    ///
+    /// - returns: The updated access token.
+    private func updateAccessToken(accessToken: OAuthAccessToken) -> OAuthAccessToken {
+        var updatedAccessToken = accessToken
+        
+        if accessToken.refreshToken == nil {
+            if let storedRefreshToken = self.accessToken?.refreshToken {
+                updatedAccessToken = accessToken.copy(refreshToken: storedRefreshToken)
+            }
+        }
+        
+        accessTokenStore.storeAccessToken(updatedAccessToken)
+        return updatedAccessToken
+    }
 
     /// Alters the given request by adding authentication with an access token.
     ///
diff --git a/HeimdallrTests/Core/HeimdallrSpec.swift b/HeimdallrTests/Core/HeimdallrSpec.swift
index f5385b4..ed1bd3d 100644
--- a/HeimdallrTests/Core/HeimdallrSpec.swift
+++ b/HeimdallrTests/Core/HeimdallrSpec.swift
@@ -667,6 +667,36 @@ class HeimdallrSpec: QuickSpec {
                 }
 
                 context("when refreshing the access token succeeds") {
+                    beforeEach {
+                        OHHTTPStubs.stubRequestsPassingTest({ request in
+                            return (request.URL!.absoluteString == "http://rheinfabrik.de")
+                            }, withStubResponse: { request in
+                                return OHHTTPStubsResponse(data: NSData(contentsOfFile: self.bundle.pathForResource("request-valid-norefresh", ofType: "json")!)!, statusCode: 200, headers: [ "Content-Type": "application/json" ])
+                        })
+                        
+                        waitUntil { done in
+                            heimdallr.authenticateRequest(request) { result = $0; done() }
+                        }
+                    }
+                    
+                    it("succeeds") {
+                        expect(result?.value).toNot(beNil())
+                    }
+                    
+                    it("attempts to parse the fresh token") {
+                        expect(accessTokenParser.timesCalled).to(equal(2))
+                    }
+                    
+                    it("authenticates the request using the resource request authenticator") {
+                        expect(result?.value?.valueForHTTPHeaderField("MockAuthorized")).to(equal("totally"))
+                    }
+                    
+                    it("keeps the original refresh token") {
+                        expect(accessTokenStore.retrieveAccessToken()?.refreshToken).to(equal("ZmVhMThjYzUyZDM3MmIzNDcyMDMyMzc2MzhmYTg4YWM0MWYyYmQxZmFlMTE2Mzk0MWY5YTk1YWQ4ZDBmYzIxZA"))
+                    }
+                }
+                
+                context("when refreshing the access token succeeds and overrides the refresh token") {
                     beforeEach {
                         OHHTTPStubs.stubRequestsPassingTest({ request in
                             return (request.URL!.absoluteString == "http://rheinfabrik.de")
@@ -690,6 +720,10 @@ class HeimdallrSpec: QuickSpec {
                     it("authenticates the request using the resource request authenticator") {
                         expect(result?.value?.valueForHTTPHeaderField("MockAuthorized")).to(equal("totally"))
                     }
+                    
+                    it("overrides the refresh token") {
+                        expect(accessTokenStore.retrieveAccessToken()?.refreshToken).to(equal("Vs25754VHY5CSovX2GRgLCLbKKZk8BQl7vmAoRav2agcY75uz338NyassLQCM8MeF04clqvtBeXG5o2wiuiTay"))
+                    }
                 }
 
                 context("when refreshing the access token fails") {
diff --git a/HeimdallrTests/Core/JSON Responses/request-valid-norefresh.json b/HeimdallrTests/Core/JSON Responses/request-valid-norefresh.json
new file mode 100644
index 0000000..4f2ddc2
--- /dev/null
+++ b/HeimdallrTests/Core/JSON Responses/request-valid-norefresh.json	
@@ -0,0 +1 @@
+{"access_token":"MTQzM2U3YTI3YmQyOWQ5YzQ0NjY4YTZkYjM0MjczYmZhNWI1M2YxM2Y1MjgwYTg3NDk3ZDc4ZGUzM2YxZmJjZQ","expires_in":65536,"token_type":"bearer","scope":"user"}
diff --git a/HeimdallrTests/Core/JSON Responses/request-valid.json b/HeimdallrTests/Core/JSON Responses/request-valid.json
index e30f229..ce191a8 100644
--- a/HeimdallrTests/Core/JSON Responses/request-valid.json	
+++ b/HeimdallrTests/Core/JSON Responses/request-valid.json	
@@ -1 +1 @@
-{"access_token":"MTQzM2U3YTI3YmQyOWQ5YzQ0NjY4YTZkYjM0MjczYmZhNWI1M2YxM2Y1MjgwYTg3NDk3ZDc4ZGUzM2YxZmJjZQ","expires_in":65536,"token_type":"bearer","scope":"user","refresh_token":"ZmVhMThjYzUyZDM3MmIzNDcyMDMyMzc2MzhmYTg4YWM0MWYyYmQxZmFlMTE2Mzk0MWY5YTk1YWQ4ZDBmYzIxZA"}
+{"access_token":"MTQzM2U3YTI3YmQyOWQ5YzQ0NjY4YTZkYjM0MjczYmZhNWI1M2YxM2Y1MjgwYTg3NDk3ZDc4ZGUzM2YxZmJjZQ","expires_in":65536,"token_type":"bearer","scope":"user","refresh_token":"Vs25754VHY5CSovX2GRgLCLbKKZk8BQl7vmAoRav2agcY75uz338NyassLQCM8MeF04clqvtBeXG5o2wiuiTay"}