diff --git a/CGDWebServer/GCDWebServerConnection.m b/CGDWebServer/GCDWebServerConnection.m
index 03afa62..1735a32 100644
--- a/CGDWebServer/GCDWebServerConnection.m
+++ b/CGDWebServer/GCDWebServerConnection.m
@@ -157,7 +157,7 @@ static dispatch_queue_t _formatterQueue = NULL;
       if (remainingLength >= 0) {
         bool success = dispatch_data_apply(buffer, ^bool(dispatch_data_t region, size_t offset, const void* buffer, size_t size) {
           NSInteger result = [_request write:buffer maxLength:size];
-          if (result != size) {
+          if (result != (NSInteger)size) {
             LOG_ERROR(@"Failed writing request body on socket %i (error %i)", _socket, (int)result);
             return false;
           }
@@ -173,8 +173,8 @@ static dispatch_queue_t _formatterQueue = NULL;
           block(NO);
         }
       } else {
-        DNOT_REACHED();
         block(NO);
+        DNOT_REACHED();
       }
     } else {
       block(NO);
@@ -360,7 +360,7 @@ static dispatch_queue_t _formatterQueue = NULL;
     NSInteger length = _request.contentLength;
     if (initialData.length) {
       NSInteger result = [_request write:initialData.bytes maxLength:initialData.length];
-      if (result == initialData.length) {
+      if (result == (NSInteger)initialData.length) {
         length -= initialData.length;
         DCHECK(length >= 0);
       } else {
diff --git a/CGDWebServer/GCDWebServerRequest.m b/CGDWebServer/GCDWebServerRequest.m
index 0aabac7..39bf771 100644
--- a/CGDWebServer/GCDWebServerRequest.m
+++ b/CGDWebServer/GCDWebServerRequest.m
@@ -529,7 +529,7 @@ static NSStringEncoding _StringEncodingFromCharset(NSString* charset) {
           NSUInteger dataLength = range.location - 2;
           if (_tmpPath) {
             ssize_t result = write(_tmpFile, dataBytes, dataLength);
-            if (result == dataLength) {
+            if (result == (ssize_t)dataLength) {
               if (close(_tmpFile) == 0) {
                 _tmpFile = 0;
                 GCDWebServerMultiPartFile* file = [[GCDWebServerMultiPartFile alloc] initWithContentType:_contentType fileName:_fileName temporaryPath:_tmpPath];
@@ -567,7 +567,7 @@ static NSStringEncoding _StringEncodingFromCharset(NSString* charset) {
       if (_tmpPath && (_parserData.length > margin)) {
         NSUInteger length = _parserData.length - margin;
         ssize_t result = write(_tmpFile, _parserData.bytes, length);
-        if (result == length) {
+        if (result == (ssize_t)length) {
           [_parserData replaceBytesInRange:NSMakeRange(0, length) withBytes:NULL length:0];
         } else {
           DNOT_REACHED();
diff --git a/CGDWebServer/GCDWebServerResponse.m b/CGDWebServer/GCDWebServerResponse.m
index 47f3a73..9076ddb 100644
--- a/CGDWebServer/GCDWebServerResponse.m
+++ b/CGDWebServer/GCDWebServerResponse.m
@@ -181,7 +181,7 @@
 - (NSInteger)read:(void*)buffer maxLength:(NSUInteger)length {
   DCHECK(_offset >= 0);
   NSInteger size = 0;
-  if (_offset < _data.length) {
+  if (_offset < (NSInteger)_data.length) {
     size = MIN(_data.length - _offset, length);
     bcopy((char*)_data.bytes + _offset, buffer, size);
     _offset += size;
@@ -282,10 +282,10 @@
   }
   if ((range.location != NSNotFound) || (range.length > 0)) {
     if (range.location != NSNotFound) {
-      range.location = MIN(range.location, info.st_size);
+      range.location = MIN(range.location, (NSUInteger)info.st_size);
       range.length = MIN(range.length, info.st_size - range.location);
     } else {
-      range.length = MIN(range.length, info.st_size);
+      range.length = MIN(range.length, (NSUInteger)info.st_size);
       range.location = info.st_size - range.length;
     }
     if (range.length == 0) {
@@ -337,7 +337,7 @@
   if (_file <= 0) {
     return NO;
   }
-  if (lseek(_file, _offset, SEEK_SET) != _offset) {
+  if (lseek(_file, _offset, SEEK_SET) != (off_t)_offset) {
     close(_file);
     _file = 0;
     return NO;
diff --git a/GCDWebServer.xcodeproj/project.pbxproj b/GCDWebServer.xcodeproj/project.pbxproj
index a50debf..2bcd48a 100644
--- a/GCDWebServer.xcodeproj/project.pbxproj
+++ b/GCDWebServer.xcodeproj/project.pbxproj
@@ -314,7 +314,16 @@
 				CLANG_ENABLE_OBJC_ARC = YES;
 				GCC_OPTIMIZATION_LEVEL = 0;
 				ONLY_ACTIVE_ARCH = YES;
-				WARNING_CFLAGS = "-Wall";
+				WARNING_CFLAGS = (
+					"-Wall",
+					"-Weverything",
+					"-Wno-gnu-statement-expression",
+					"-Wno-direct-ivar-access",
+					"-Wno-implicit-retain-self",
+					"-Wno-assign-enum",
+					"-Wno-format-nonliteral",
+					"-Wno-cast-align",
+				);
 			};
 			name = Debug;
 		};
@@ -323,6 +332,7 @@
 			buildSettings = {
 				CLANG_ENABLE_OBJC_ARC = YES;
 				GCC_PREPROCESSOR_DEFINITIONS = NDEBUG;
+				GCC_TREAT_WARNINGS_AS_ERRORS = YES;
 				WARNING_CFLAGS = "-Wall";
 			};
 			name = Release;