diff --git a/Source/Request+AlamofireImage.swift b/Source/Request+AlamofireImage.swift
index cbe280f3..ca9019b6 100644
--- a/Source/Request+AlamofireImage.swift
+++ b/Source/Request+AlamofireImage.swift
@@ -33,6 +33,27 @@ import Cocoa
 #endif
 
 extension Request {
+    static var acceptableImageContentTypes: Set<String> = [
+        "image/tiff",
+        "image/jpeg",
+        "image/gif",
+        "image/png",
+        "image/ico",
+        "image/x-icon",
+        "image/bmp",
+        "image/x-bmp",
+        "image/x-xbitmap",
+        "image/x-win-bitmap"
+    ]
+
+    /**
+        Adds the content types specified to the list of acceptable images content types for validation.
+
+        - parameter contentTypes: The additional content types.
+    */
+    public class func addAcceptableImageContentTypes(contentTypes: Set<String>) {
+        Request.acceptableImageContentTypes.unionInPlace(contentTypes)
+    }
 
     // MARK: - iOS and watchOS
 
@@ -195,20 +216,7 @@ extension Request {
             return true
         }
 
-        let acceptableContentTypes: Set<String> = [
-            "image/tiff",
-            "image/jpeg",
-            "image/gif",
-            "image/png",
-            "image/ico",
-            "image/x-icon",
-            "image/bmp",
-            "image/x-bmp",
-            "image/x-xbitmap",
-            "image/x-win-bitmap"
-        ]
-
-        if let mimeType = response?.MIMEType where acceptableContentTypes.contains(mimeType) {
+        if let mimeType = response?.MIMEType where Request.acceptableImageContentTypes.contains(mimeType) {
             return true
         }
 
diff --git a/Tests/RequestTests.swift b/Tests/RequestTests.swift
index b1b1ea93..98afc430 100644
--- a/Tests/RequestTests.swift
+++ b/Tests/RequestTests.swift
@@ -21,11 +21,40 @@
 // THE SOFTWARE.
 
 import Alamofire
-import AlamofireImage
+@testable import AlamofireImage
 import Foundation
 import XCTest
 
 class RequestTestCase: BaseTestCase {
+    var acceptableImageContentTypes: Set<String>!
+
+    // MARK: - Setup and Teardown
+
+    override func setUp() {
+        super.setUp()
+        acceptableImageContentTypes = Request.acceptableImageContentTypes
+    }
+
+    override func tearDown() {
+        super.tearDown()
+        Request.acceptableImageContentTypes = acceptableImageContentTypes
+    }
+
+    // MARK: - Image Content Type Tests
+
+    func testThatAddingAcceptableImageContentTypesInsertsThemIntoTheGlobalList() {
+        // Given
+        let contentTypes: Set<String> = ["image/jpg", "binary/octet-stream"]
+
+        // When
+        let beforeCount = Request.acceptableImageContentTypes.count
+        Request.addAcceptableImageContentTypes(contentTypes)
+        let afterCount = Request.acceptableImageContentTypes.count
+
+        // Then
+        XCTAssertEqual(beforeCount, 10, "before count should be 10")
+        XCTAssertEqual(afterCount, 12, "after count should be 12")
+    }
 
     // MARK: - Image Serialization Tests