diff --git a/CGDWebServer/GCDWebServer.m b/CGDWebServer/GCDWebServer.m
index 552f6fe..179bbbe 100644
--- a/CGDWebServer/GCDWebServer.m
+++ b/CGDWebServer/GCDWebServer.m
@@ -652,7 +652,7 @@ static void _NetServiceClientCallBack(CFNetServiceRef service, CFStreamError* er
       if (response) {
         response.cacheControlMaxAge = cacheAge;
       } else {
-        response = [GCDWebServerResponse responseWithClientError:kGCDWebServerHTTPStatusCode_NotFound];
+        response = [GCDWebServerResponse responseWithStatusCode:kGCDWebServerHTTPStatusCode_NotFound];
       }
       return response;
       
diff --git a/CGDWebServer/GCDWebServerErrorResponse.h b/CGDWebServer/GCDWebServerErrorResponse.h
new file mode 100644
index 0000000..9e51a45
--- /dev/null
+++ b/CGDWebServer/GCDWebServerErrorResponse.h
@@ -0,0 +1,41 @@
+/*
+ Copyright (c) 2012-2014, Pierre-Olivier Latour
+ All rights reserved.
+ 
+ Redistribution and use in source and binary forms, with or without
+ modification, are permitted provided that the following conditions are met:
+ * Redistributions of source code must retain the above copyright
+ notice, this list of conditions and the following disclaimer.
+ * Redistributions in binary form must reproduce the above copyright
+ notice, this list of conditions and the following disclaimer in the
+ documentation and/or other materials provided with the distribution.
+ * The name of Pierre-Olivier Latour may not be used to endorse
+ or promote products derived from this software without specific
+ prior written permission.
+ 
+ THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ DISCLAIMED. IN NO EVENT SHALL PIERRE-OLIVIER LATOUR BE LIABLE FOR ANY
+ DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#import "GCDWebServerDataResponse.h"
+#import "GCDWebServerHTTPStatusCodes.h"
+
+// Returns responses with an HTML body containing the error message
+@interface GCDWebServerErrorResponse : GCDWebServerDataResponse
++ (GCDWebServerErrorResponse*)responseWithClientError:(GCDWebServerClientErrorHTTPStatusCode)errorCode message:(NSString*)format, ... NS_FORMAT_FUNCTION(2,3);
++ (GCDWebServerErrorResponse*)responseWithServerError:(GCDWebServerServerErrorHTTPStatusCode)errorCode message:(NSString*)format, ... NS_FORMAT_FUNCTION(2,3);
++ (GCDWebServerErrorResponse*)responseWithClientError:(GCDWebServerClientErrorHTTPStatusCode)errorCode underlyingError:(NSError*)underlyingError message:(NSString*)format, ... NS_FORMAT_FUNCTION(3,4);
++ (GCDWebServerErrorResponse*)responseWithServerError:(GCDWebServerServerErrorHTTPStatusCode)errorCode underlyingError:(NSError*)underlyingError message:(NSString*)format, ... NS_FORMAT_FUNCTION(3,4);
+- (id)initWithClientError:(GCDWebServerClientErrorHTTPStatusCode)errorCode message:(NSString*)format, ... NS_FORMAT_FUNCTION(2,3);
+- (id)initWithServerError:(GCDWebServerServerErrorHTTPStatusCode)errorCode message:(NSString*)format, ... NS_FORMAT_FUNCTION(2,3);
+- (id)initWithClientError:(GCDWebServerClientErrorHTTPStatusCode)errorCode underlyingError:(NSError*)underlyingError message:(NSString*)format, ... NS_FORMAT_FUNCTION(3,4);
+- (id)initWithServerError:(GCDWebServerServerErrorHTTPStatusCode)errorCode underlyingError:(NSError*)underlyingError message:(NSString*)format, ... NS_FORMAT_FUNCTION(3,4);
+@end
diff --git a/CGDWebServer/GCDWebServerErrorResponse.m b/CGDWebServer/GCDWebServerErrorResponse.m
new file mode 100644
index 0000000..abc368a
--- /dev/null
+++ b/CGDWebServer/GCDWebServerErrorResponse.m
@@ -0,0 +1,125 @@
+/*
+ Copyright (c) 2012-2014, Pierre-Olivier Latour
+ All rights reserved.
+ 
+ Redistribution and use in source and binary forms, with or without
+ modification, are permitted provided that the following conditions are met:
+ * Redistributions of source code must retain the above copyright
+ notice, this list of conditions and the following disclaimer.
+ * Redistributions in binary form must reproduce the above copyright
+ notice, this list of conditions and the following disclaimer in the
+ documentation and/or other materials provided with the distribution.
+ * The name of Pierre-Olivier Latour may not be used to endorse
+ or promote products derived from this software without specific
+ prior written permission.
+ 
+ THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ DISCLAIMED. IN NO EVENT SHALL PIERRE-OLIVIER LATOUR BE LIABLE FOR ANY
+ DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#import "GCDWebServerPrivate.h"
+
+@interface GCDWebServerErrorResponse ()
+- (id)initWithStatusCode:(NSInteger)statusCode underlyingError:(NSError*)underlyingError messageFormat:(NSString*)format arguments:(va_list)arguments;
+@end
+
+@implementation GCDWebServerErrorResponse
+
++ (GCDWebServerErrorResponse*)responseWithClientError:(GCDWebServerClientErrorHTTPStatusCode)errorCode message:(NSString*)format, ... {
+  DCHECK(((NSInteger)errorCode >= 400) && ((NSInteger)errorCode < 500));
+  va_list arguments;
+  va_start(arguments, format);
+  GCDWebServerErrorResponse* response = ARC_AUTORELEASE([[self alloc] initWithStatusCode:errorCode underlyingError:nil messageFormat:format arguments:arguments]);
+  va_end(arguments);
+  return response;
+}
+
++ (GCDWebServerErrorResponse*)responseWithServerError:(GCDWebServerServerErrorHTTPStatusCode)errorCode message:(NSString*)format, ... {
+  DCHECK(((NSInteger)errorCode >= 500) && ((NSInteger)errorCode < 600));
+  va_list arguments;
+  va_start(arguments, format);
+  GCDWebServerErrorResponse* response = ARC_AUTORELEASE([[self alloc] initWithStatusCode:errorCode underlyingError:nil messageFormat:format arguments:arguments]);
+  va_end(arguments);
+  return response;
+}
+
++ (GCDWebServerErrorResponse*)responseWithClientError:(GCDWebServerClientErrorHTTPStatusCode)errorCode underlyingError:(NSError*)underlyingError message:(NSString*)format, ... {
+  DCHECK(((NSInteger)errorCode >= 400) && ((NSInteger)errorCode < 500));
+  va_list arguments;
+  va_start(arguments, format);
+  GCDWebServerErrorResponse* response = ARC_AUTORELEASE([[self alloc] initWithStatusCode:errorCode underlyingError:underlyingError messageFormat:format arguments:arguments]);
+  va_end(arguments);
+  return response;
+}
+
++ (GCDWebServerErrorResponse*)responseWithServerError:(GCDWebServerServerErrorHTTPStatusCode)errorCode underlyingError:(NSError*)underlyingError message:(NSString*)format, ... {
+  DCHECK(((NSInteger)errorCode >= 500) && ((NSInteger)errorCode < 600));
+  va_list arguments;
+  va_start(arguments, format);
+  GCDWebServerErrorResponse* response = ARC_AUTORELEASE([[self alloc] initWithStatusCode:errorCode underlyingError:underlyingError messageFormat:format arguments:arguments]);
+  va_end(arguments);
+  return response;
+}
+
+static inline NSString* _EscapeHTMLString(NSString* string) {
+  return [string stringByReplacingOccurrencesOfString:@"\"" withString:@"&quot;"];
+}
+
+- (id)initWithStatusCode:(NSInteger)statusCode underlyingError:(NSError*)underlyingError messageFormat:(NSString*)format arguments:(va_list)arguments {
+  NSString* message = [[NSString alloc] initWithFormat:format arguments:arguments];
+  NSString* title = [NSString stringWithFormat:@"HTTP Error %i", (int)statusCode];
+  NSString* error = underlyingError ? [NSString stringWithFormat:@"[%@] %@ (%li)", underlyingError.domain, _EscapeHTMLString(underlyingError.localizedDescription), (long)underlyingError.code] : @"";
+  NSString* html = [NSString stringWithFormat:@"<!DOCTYPE html><html lang=\"en\"><head><meta charset=\"utf-8\"><title>%@</title></head><body><h1>%@: %@</h1><h3>%@</h3></body></html>",
+                                              title, title, _EscapeHTMLString(message), error];
+  if ((self = [self initWithHTML:html])) {
+    self.statusCode = statusCode;
+  }
+  ARC_RELEASE(message);
+  return self;
+}
+
+- (id)initWithClientError:(GCDWebServerClientErrorHTTPStatusCode)errorCode message:(NSString*)format, ... {
+  DCHECK(((NSInteger)errorCode >= 400) && ((NSInteger)errorCode < 500));
+  va_list arguments;
+  va_start(arguments, format);
+  self = [self initWithStatusCode:errorCode underlyingError:nil messageFormat:format arguments:arguments];
+  va_end(arguments);
+  return self;
+}
+
+- (id)initWithServerError:(GCDWebServerServerErrorHTTPStatusCode)errorCode message:(NSString*)format, ... {
+  DCHECK(((NSInteger)errorCode >= 500) && ((NSInteger)errorCode < 600));
+  va_list arguments;
+  va_start(arguments, format);
+  self = [self initWithStatusCode:errorCode underlyingError:nil messageFormat:format arguments:arguments];
+  va_end(arguments);
+  return self;
+}
+
+- (id)initWithClientError:(GCDWebServerClientErrorHTTPStatusCode)errorCode underlyingError:(NSError*)underlyingError message:(NSString*)format, ... {
+  DCHECK(((NSInteger)errorCode >= 400) && ((NSInteger)errorCode < 500));
+  va_list arguments;
+  va_start(arguments, format);
+  self = [self initWithStatusCode:errorCode underlyingError:underlyingError messageFormat:format arguments:arguments];
+  va_end(arguments);
+  return self;
+}
+
+- (id)initWithServerError:(GCDWebServerServerErrorHTTPStatusCode)errorCode underlyingError:(NSError*)underlyingError message:(NSString*)format, ... {
+  DCHECK(((NSInteger)errorCode >= 500) && ((NSInteger)errorCode < 600));
+  va_list arguments;
+  va_start(arguments, format);
+  self = [self initWithStatusCode:errorCode underlyingError:underlyingError messageFormat:format arguments:arguments];
+  va_end(arguments);
+  return self;
+}
+
+@end
diff --git a/CGDWebServer/GCDWebServerPrivate.h b/CGDWebServer/GCDWebServerPrivate.h
index 1915aa5..08662c2 100644
--- a/CGDWebServer/GCDWebServerPrivate.h
+++ b/CGDWebServer/GCDWebServerPrivate.h
@@ -60,6 +60,7 @@
 #import "GCDWebServerURLEncodedFormRequest.h"
 
 #import "GCDWebServerDataResponse.h"
+#import "GCDWebServerErrorResponse.h"
 #import "GCDWebServerFileResponse.h"
 #import "GCDWebServerStreamingResponse.h"
 
diff --git a/CGDWebServer/GCDWebServerResponse.h b/CGDWebServer/GCDWebServerResponse.h
index 18470a0..ead69e5 100644
--- a/CGDWebServer/GCDWebServerResponse.h
+++ b/CGDWebServer/GCDWebServerResponse.h
@@ -25,7 +25,7 @@
  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#import "GCDWebServerHTTPStatusCodes.h"
+#import <Foundation/Foundation.h>
 
 @protocol GCDWebServerBodyReader <NSObject>
 - (BOOL)open:(NSError**)error;  // Return NO on error ("error" is guaranteed to be non-NULL)
@@ -47,11 +47,7 @@
 
 @interface GCDWebServerResponse (Extensions)
 + (GCDWebServerResponse*)responseWithStatusCode:(NSInteger)statusCode;
-+ (GCDWebServerResponse*)responseWithClientError:(GCDWebServerClientErrorHTTPStatusCode)error;
-+ (GCDWebServerResponse*)responseWithServerError:(GCDWebServerServerErrorHTTPStatusCode)error;
 + (GCDWebServerResponse*)responseWithRedirect:(NSURL*)location permanent:(BOOL)permanent;
 - (id)initWithStatusCode:(NSInteger)statusCode;
-- (id)initWithClientError:(GCDWebServerClientErrorHTTPStatusCode)error;
-- (id)initWithServerError:(GCDWebServerServerErrorHTTPStatusCode)error;
 - (id)initWithRedirect:(NSURL*)location permanent:(BOOL)permanent;
 @end
diff --git a/CGDWebServer/GCDWebServerResponse.m b/CGDWebServer/GCDWebServerResponse.m
index e3e5085..4cc88e6 100644
--- a/CGDWebServer/GCDWebServerResponse.m
+++ b/CGDWebServer/GCDWebServerResponse.m
@@ -252,14 +252,6 @@
   return ARC_AUTORELEASE([[self alloc] initWithStatusCode:statusCode]);
 }
 
-+ (GCDWebServerResponse*)responseWithClientError:(GCDWebServerClientErrorHTTPStatusCode)error {
-  return ARC_AUTORELEASE([[self alloc] initWithClientError:error]);
-}
-
-+ (GCDWebServerResponse*)responseWithServerError:(GCDWebServerServerErrorHTTPStatusCode)error {
-  return ARC_AUTORELEASE([[self alloc] initWithServerError:error]);
-}
-
 + (GCDWebServerResponse*)responseWithRedirect:(NSURL*)location permanent:(BOOL)permanent {
   return ARC_AUTORELEASE([[self alloc] initWithRedirect:location permanent:permanent]);
 }
@@ -271,16 +263,6 @@
   return self;
 }
 
-- (id)initWithClientError:(GCDWebServerClientErrorHTTPStatusCode)error {
-  DCHECK(((NSInteger)error >= 400) && ((NSInteger)error < 500));
-  return [self initWithStatusCode:error];
-}
-
-- (id)initWithServerError:(GCDWebServerServerErrorHTTPStatusCode)error {
-  DCHECK(((NSInteger)error >= 500) && ((NSInteger)error < 600));
-  return [self initWithStatusCode:error];
-}
-
 - (id)initWithRedirect:(NSURL*)location permanent:(BOOL)permanent {
   if ((self = [self init])) {
     self.statusCode = permanent ? kGCDWebServerHTTPStatusCode_MovedPermanently : kGCDWebServerHTTPStatusCode_TemporaryRedirect;
diff --git a/GCDWebServer.xcodeproj/project.pbxproj b/GCDWebServer.xcodeproj/project.pbxproj
index 8e9e4a9..79dd7ca 100644
--- a/GCDWebServer.xcodeproj/project.pbxproj
+++ b/GCDWebServer.xcodeproj/project.pbxproj
@@ -38,6 +38,8 @@
 		E22112991690B7AA0048D2B2 /* CFNetwork.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = E22112981690B7AA0048D2B2 /* CFNetwork.framework */; };
 		E221129B1690B7B10048D2B2 /* UIKit.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = E221129A1690B7B10048D2B2 /* UIKit.framework */; };
 		E221129D1690B7BA0048D2B2 /* MobileCoreServices.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = E221129C1690B7BA0048D2B2 /* MobileCoreServices.framework */; };
+		E276647C18F3BC2100A034BA /* GCDWebServerErrorResponse.m in Sources */ = {isa = PBXBuildFile; fileRef = E276647B18F3BC2100A034BA /* GCDWebServerErrorResponse.m */; };
+		E276647D18F3BC2100A034BA /* GCDWebServerErrorResponse.m in Sources */ = {isa = PBXBuildFile; fileRef = E276647B18F3BC2100A034BA /* GCDWebServerErrorResponse.m */; };
 		E2A0E7ED18F1D03700C580B1 /* GCDWebServerDataResponse.m in Sources */ = {isa = PBXBuildFile; fileRef = E2A0E7EC18F1D03700C580B1 /* GCDWebServerDataResponse.m */; };
 		E2A0E7EE18F1D03700C580B1 /* GCDWebServerDataResponse.m in Sources */ = {isa = PBXBuildFile; fileRef = E2A0E7EC18F1D03700C580B1 /* GCDWebServerDataResponse.m */; };
 		E2A0E7F118F1D12E00C580B1 /* GCDWebServerFileResponse.m in Sources */ = {isa = PBXBuildFile; fileRef = E2A0E7F018F1D12E00C580B1 /* GCDWebServerFileResponse.m */; };
@@ -113,6 +115,8 @@
 		E22112981690B7AA0048D2B2 /* CFNetwork.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = CFNetwork.framework; path = Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS6.0.sdk/System/Library/Frameworks/CFNetwork.framework; sourceTree = DEVELOPER_DIR; };
 		E221129A1690B7B10048D2B2 /* UIKit.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = UIKit.framework; path = Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS6.0.sdk/System/Library/Frameworks/UIKit.framework; sourceTree = DEVELOPER_DIR; };
 		E221129C1690B7BA0048D2B2 /* MobileCoreServices.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = MobileCoreServices.framework; path = Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS6.0.sdk/System/Library/Frameworks/MobileCoreServices.framework; sourceTree = DEVELOPER_DIR; };
+		E276647A18F3BC2100A034BA /* GCDWebServerErrorResponse.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = GCDWebServerErrorResponse.h; sourceTree = "<group>"; };
+		E276647B18F3BC2100A034BA /* GCDWebServerErrorResponse.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = GCDWebServerErrorResponse.m; sourceTree = "<group>"; };
 		E2A0E7EB18F1D03700C580B1 /* GCDWebServerDataResponse.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = GCDWebServerDataResponse.h; sourceTree = "<group>"; };
 		E2A0E7EC18F1D03700C580B1 /* GCDWebServerDataResponse.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = GCDWebServerDataResponse.m; sourceTree = "<group>"; };
 		E2A0E7EF18F1D12E00C580B1 /* GCDWebServerFileResponse.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = GCDWebServerFileResponse.h; sourceTree = "<group>"; };
@@ -196,6 +200,8 @@
 				E2A0E7F818F1D24700C580B1 /* GCDWebServerDataRequest.m */,
 				E2A0E7EB18F1D03700C580B1 /* GCDWebServerDataResponse.h */,
 				E2A0E7EC18F1D03700C580B1 /* GCDWebServerDataResponse.m */,
+				E276647A18F3BC2100A034BA /* GCDWebServerErrorResponse.h */,
+				E276647B18F3BC2100A034BA /* GCDWebServerErrorResponse.m */,
 				E2A0E7FB18F1D36C00C580B1 /* GCDWebServerFileRequest.h */,
 				E2A0E7FC18F1D36C00C580B1 /* GCDWebServerFileRequest.m */,
 				E2A0E7EF18F1D12E00C580B1 /* GCDWebServerFileResponse.h */,
@@ -357,6 +363,7 @@
 				E2A0E80518F1D4A700C580B1 /* GCDWebServerURLEncodedFormRequest.m in Sources */,
 				E2A0E7F918F1D24700C580B1 /* GCDWebServerDataRequest.m in Sources */,
 				E22112891690B63A0048D2B2 /* GCDWebServerRequest.m in Sources */,
+				E276647C18F3BC2100A034BA /* GCDWebServerErrorResponse.m in Sources */,
 				E2A0E7ED18F1D03700C580B1 /* GCDWebServerDataResponse.m in Sources */,
 				E2A0E7F518F1D1E500C580B1 /* GCDWebServerStreamingResponse.m in Sources */,
 				E2A0E80118F1D3DE00C580B1 /* GCDWebServerMultiPartFormRequest.m in Sources */,
@@ -372,6 +379,7 @@
 			buildActionMask = 2147483647;
 			files = (
 				E22112861690B63A0048D2B2 /* GCDWebServer.m in Sources */,
+				E276647D18F3BC2100A034BA /* GCDWebServerErrorResponse.m in Sources */,
 				E2A0E7EE18F1D03700C580B1 /* GCDWebServerDataResponse.m in Sources */,
 				E2A0E80218F1D3DE00C580B1 /* GCDWebServerMultiPartFormRequest.m in Sources */,
 				E22112881690B63A0048D2B2 /* GCDWebServerConnection.m in Sources */,