diff --git a/Squirrel/SQRLUpdater.h b/Squirrel/SQRLUpdater.h
index 8e780396..56f7fb19 100644
--- a/Squirrel/SQRLUpdater.h
+++ b/Squirrel/SQRLUpdater.h
@@ -67,6 +67,12 @@ extern NSString * const SQRLUpdaterJSONObjectErrorKey;
 @class RACDisposable;
 @class RACSignal;
 
+/// Type of mode used to download the release
+typedef enum {
+	JSONFILE=1,
+	RELEASESERVER
+} SQRLUpdaterMode;
+
 // Checks for, downloads, and installs updates.
 @interface SQRLUpdater : NSObject
 
@@ -123,6 +129,19 @@ extern NSString * const SQRLUpdaterJSONObjectErrorKey;
 // Returns the initialized `SQRLUpdater`.
 - (id)initWithUpdateRequest:(NSURLRequest *)updateRequest;
 
+// Initializes an updater that will send the given request to check for updates
+// on a CDN reading a release file in json format.
+//
+// updateRequest - A request to send to check for updates. This request can be
+//                 customized as desired, like by including an `Authorization`
+//                 header to authenticate with a private update server, or
+//                 pointing to a local URL for testing. This must not be nil.
+// forVersion    - the currently installed version
+//
+// Returns the initialized `SQRLUpdater`.
+- (id)initWithUpdateRequest:(NSURLRequest *)updateRequest
+					   forVersion:(NSString*)version;
+
 // Initializes an updater that will send the given request to check for updates
 // and passes a block to provide requests for the update downloads.
 //
@@ -133,7 +152,7 @@ extern NSString * const SQRLUpdaterJSONObjectErrorKey;
 //                      updateRequest param.
 //
 // Returns the initialized `SQRLUpdater`.
-- (id)initWithUpdateRequest:(NSURLRequest *)updateRequest requestForDownload:(SQRLRequestForDownload)requestForDownload;
+- (id)initWithUpdateRequest:(NSURLRequest *)updateRequest requestForDownload:(SQRLRequestForDownload)requestForDownload forVersion:(NSString*) version useMode:(SQRLUpdaterMode) mode;
 
 // Executes `checkForUpdatesCommand` (if enabled) every `interval` seconds.
 //
diff --git a/Squirrel/SQRLUpdater.m b/Squirrel/SQRLUpdater.m
index 3581215f..9f1d3e6a 100644
--- a/Squirrel/SQRLUpdater.m
+++ b/Squirrel/SQRLUpdater.m
@@ -40,12 +40,6 @@
 // followed by a random string of characters.
 static NSString * const SQRLUpdaterUniqueTemporaryDirectoryPrefix = @"update.";
 
-/// Type of mode used to download the release
-typedef enum {
-	JSONFILE=1,
-	RELEASESERVER
-} Mode;
-
 @interface SQRLUpdater ()
 
 @property (atomic, readwrite) SQRLUpdaterState state;
@@ -152,24 +146,27 @@ - (id)init {
 - (id)initWithUpdateRequest:(NSURLRequest *)updateRequest {
 	return [self initWithUpdateRequest:updateRequest requestForDownload:^(NSURL *downloadURL) {
 		return [NSURLRequest requestWithURL:downloadURL];
-	}];
+	} forVersion:@"" useMode:RELEASESERVER];
 }
 
-- (id)initWithUpdateRequest:(NSURLRequest *)updateRequest requestForDownload:(SQRLRequestForDownload)requestForDownload {
-	//! foo.bar/releases.json?version=1.0
-
-	NSString* version = getenv("VERSION") ? @(getenv("VERSION")) : @"";
+- (id)initWithUpdateRequest:(NSURLRequest *)updateRequest forVersion: (NSString*) version {
+	return [self initWithUpdateRequest:updateRequest requestForDownload:^(NSURL *downloadURL) {
+		return [NSURLRequest requestWithURL:downloadURL];
+	} forVersion:version useMode:JSONFILE];
+}
 
-	Mode mode = RELEASESERVER;
-	if(getenv("MODE")) {
-		mode = [@(getenv("MODE")) isEqualToString:@"JSONFILE"] ? JSONFILE : RELEASESERVER;
-	}
+- (id)initWithUpdateRequest:(NSURLRequest *)updateRequest requestForDownload:(SQRLRequestForDownload)requestForDownload
+				 forVersion:(NSString*) version useMode:(SQRLUpdaterMode) mode {
 
 	//! download simple file
 
 	NSParameterAssert(updateRequest != nil);
 	NSParameterAssert(requestForDownload != nil);
 
+	if(mode == JSONFILE) {
+		NSParameterAssert(version != nil);
+	}
+
 	self = [super init];
 	if (self == nil) return nil;
 
diff --git a/SquirrelTests/SQRLUpdaterSpec.m b/SquirrelTests/SQRLUpdaterSpec.m
index 25e17959..e06978a4 100644
--- a/SquirrelTests/SQRLUpdaterSpec.m
+++ b/SquirrelTests/SQRLUpdaterSpec.m
@@ -99,7 +99,7 @@ bool isRunningOnReadOnlyVolumeImp(id self, SEL _cmd)
 										 @"name": @"my-stub-release",
 										 @"notes": @"mock release for automated tests, json",
 										 @"pub_date": @"2017-03-09T15:24:55-05:00",
-										 @"url": @"http://localhost/hipchatng-0.0.145.zip"
+										 @"url": @"http://localhost/myapp-0.0.145.zip"
 										 };
 
 		NSError * err;
@@ -116,7 +116,7 @@ bool isRunningOnReadOnlyVolumeImp(id self, SEL _cmd)
 										 @"name": @"my-stub-release",
 										 @"notes": @"mock release for automated tests, release server",
 										 @"pub_date": @"2017-03-09T15:24:55-05:00",
-										 @"url": @"http://localhost/hipchatng-0.0.145.zip"
+										 @"url": @"http://localmyappng-0.0.145.zip"
 										 };
 
 		NSError * err;