diff --git a/Mocktail/Mocktail.m b/Mocktail/Mocktail.m
index 62f26bb..329628a 100644
--- a/Mocktail/Mocktail.m
+++ b/Mocktail/Mocktail.m
@@ -218,42 +218,22 @@ - (void)registerContentsOfDirectoryAtURL:(NSURL *)url;
 
 - (void)registerFileAtURL:(NSURL *)url;
 {
-    NSAssert(url, @"Expected valid URL.");
-    
-    NSError *error;
-    NSStringEncoding originalEncoding;
-    NSString *contentsOfFile = [NSString stringWithContentsOfURL:url usedEncoding:&originalEncoding error:&error];
-    if (error) {
-        NSLog(@"Error opening %@: %@", url, error);
-        return;
-    }
-    
-    NSScanner *scanner = [NSScanner scannerWithString:contentsOfFile];
-    NSString *headerMatter = nil;
-    [scanner scanUpToString:@"\n\n" intoString:&headerMatter];
-    NSArray *lines = [headerMatter componentsSeparatedByString:@"\n"];
-    if ([lines count] < 4) {
-        NSLog(@"Invalid amount of lines: %u", (unsigned)[lines count]);
-        return;
-    }
-    
-    MocktailResponse *response = [MocktailResponse new];
-    response.mocktail = self;
-    response.methodRegex = [NSRegularExpression regularExpressionWithPattern:lines[0] options:NSRegularExpressionCaseInsensitive error:nil];
-    response.absoluteURLRegex = [NSRegularExpression regularExpressionWithPattern:lines[1] options:NSRegularExpressionCaseInsensitive error:nil];
-    response.statusCode = [lines[2] integerValue];
-    NSMutableDictionary *headers = [[NSMutableDictionary alloc] init];
-    for (NSString *line in [lines subarrayWithRange:NSMakeRange(3, lines.count - 3)]) {
-        NSArray* parts = [line componentsSeparatedByString:@":"];
-        [headers setObject:[[parts lastObject] stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceCharacterSet]]
-                    forKey:[parts firstObject]];
+    NSError *mocktailResponseError;
+    MocktailResponse *response = [MocktailResponse mocktailResponseForFileAtURL:url error:&mocktailResponseError];
+
+    if (mocktailResponseError) {
+        if (mocktailResponseError.code == MocktailResponseErrorOpeningFile) {
+            NSLog(@"Error opening %@: %@", url, mocktailResponseError.userInfo[kFileErrorUserDataKey]);
+        } else if (mocktailResponseError.code == MocktailResponseErrorNumberOfLines) {
+            NSLog(@"Invalid amount of lines: %u", (unsigned)[mocktailResponseError.userInfo[kNumberOfLinesErrorUserDataKey] count]);
+        }
     }
-    response.headers = headers;
-    response.fileURL = url;
-    response.bodyOffset = [headerMatter dataUsingEncoding:originalEncoding].length + 2;
-    
+
     @synchronized (_mutableMockResponses) {
-        [_mutableMockResponses addObject:response];
+        if (response) {
+            response.mocktail = self;
+            [_mutableMockResponses addObject:response];
+        }
     }
 }
 
diff --git a/Mocktail/MocktailResponse.h b/Mocktail/MocktailResponse.h
index 37e952c..7d70b58 100644
--- a/Mocktail/MocktailResponse.h
+++ b/Mocktail/MocktailResponse.h
@@ -9,18 +9,31 @@
 
 #import <Foundation/Foundation.h>
 
+extern NSString *const kMocktailResponseErrorDomain;
+extern NSString *const kFileErrorUserDataKey;
+extern NSString *const kNumberOfLinesErrorUserDataKey;
 
-@class Mocktail;
+typedef NS_ENUM(NSInteger, MockTailResponseError) {
+    MocktailResponseErrorOpeningFile,
+    MocktailResponseErrorNumberOfLines
+};
 
+@class Mocktail;
 
 @interface MocktailResponse : NSObject
 
-@property (nonatomic, strong) NSRegularExpression *methodRegex;
-@property (nonatomic, strong) NSRegularExpression *absoluteURLRegex;
-@property (nonatomic, strong) NSURL *fileURL;
-@property (nonatomic) NSInteger bodyOffset;
-@property (nonatomic, strong) NSDictionary *headers;
-@property (nonatomic) NSInteger statusCode;
+@property (nonatomic, strong, readonly) NSRegularExpression *methodRegex;
+@property (nonatomic, strong, readonly) NSRegularExpression *absoluteURLRegex;
+@property (nonatomic, strong, readonly) NSURL *fileURL;
+@property (nonatomic, readonly) NSInteger bodyOffset;
+@property (nonatomic, strong, readonly) NSDictionary *headers;
+@property (nonatomic, readonly) NSInteger statusCode;
 @property (nonatomic, weak) Mocktail *mocktail;
 
+- (instancetype)init NS_UNAVAILABLE;
+
+- (instancetype)initWithFileAtURL:(NSURL *)fileURL error:(NSError **)error NS_DESIGNATED_INITIALIZER;
+
++ (MocktailResponse *)mocktailResponseForFileAtURL:(NSURL *)url error:(NSError **)error;
+
 @end
diff --git a/Mocktail/MocktailResponse.m b/Mocktail/MocktailResponse.m
index 7c8912d..c0fd60a 100644
--- a/Mocktail/MocktailResponse.m
+++ b/Mocktail/MocktailResponse.m
@@ -10,6 +10,68 @@
 
 #import "MocktailResponse.h"
 
+@interface MocktailResponse()
+
+@property (nonatomic, strong) NSRegularExpression *methodRegex;
+@property (nonatomic, strong) NSRegularExpression *absoluteURLRegex;
+@property (nonatomic, strong) NSURL *fileURL;
+@property (nonatomic) NSInteger bodyOffset;
+@property (nonatomic, strong) NSDictionary *headers;
+@property (nonatomic) NSInteger statusCode;
+
+@end
+
+NSString *const kMocktailResponseErrorDomain = @"MocktailResponseError";
+NSString *const kFileErrorUserDataKey = @"fileError";
+NSString *const kNumberOfLinesErrorUserDataKey = @"lines";
+static NSUInteger const kNumLinesRequired = 4;
 
 @implementation MocktailResponse
+
+- (instancetype)initWithFileAtURL:(NSURL *)url error:(NSError *__autoreleasing *)error {
+    self = [super init];
+    if (self) {
+        NSError *fileError;
+        NSStringEncoding originalEncoding;
+        NSString *contentsOfFile = [NSString stringWithContentsOfURL:url usedEncoding:&originalEncoding error:&fileError];
+        if (fileError) {
+            *error = [[NSError alloc] initWithDomain:kMocktailResponseErrorDomain
+                                                code:MocktailResponseErrorOpeningFile
+                                            userInfo:@{kFileErrorUserDataKey: fileError}];
+            return nil;
+        }
+
+        NSScanner *scanner = [NSScanner scannerWithString:contentsOfFile];
+        NSString *headerMatter = nil;
+        [scanner scanUpToString:@"\n\n" intoString:&headerMatter];
+        NSArray *lines = [headerMatter componentsSeparatedByString:@"\n"];
+        if ([lines count] < kNumLinesRequired) {
+            *error = [[NSError alloc] initWithDomain:kMocktailResponseErrorDomain
+                                                code:MocktailResponseErrorNumberOfLines
+                                            userInfo:@{kNumberOfLinesErrorUserDataKey: lines}];
+            return nil;
+        }
+
+        _methodRegex = [NSRegularExpression regularExpressionWithPattern:lines[0] options:NSRegularExpressionCaseInsensitive error:nil];
+        _absoluteURLRegex = [NSRegularExpression regularExpressionWithPattern:lines[1] options:NSRegularExpressionCaseInsensitive error:nil];
+        _statusCode = [lines[2] integerValue];
+        NSMutableDictionary *headers = [[NSMutableDictionary alloc] init];
+        for (NSString *line in [lines subarrayWithRange:NSMakeRange(3, lines.count - 3)]) {
+            NSArray* parts = [line componentsSeparatedByString:@":"];
+            headers[[parts firstObject]] = [[parts lastObject] stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceCharacterSet]];
+        }
+        _headers = headers;
+        _fileURL = url;
+        _bodyOffset = [headerMatter dataUsingEncoding:originalEncoding].length + 2;
+    }
+
+    return self;
+}
+
++ (MocktailResponse *)mocktailResponseForFileAtURL:(NSURL *)url error:(NSError *__autoreleasing *)error {
+    NSAssert(url, @"Expected valid URL.");
+
+    return [[MocktailResponse alloc] initWithFileAtURL:url error:error];
+}
+
 @end