diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 5f4432c2..45971ce2 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -95,7 +95,7 @@ default:
     - - |
           # apt_common
           echo -e "\e[0Ksection_start:`date +%s`:apt_common[collapsed=true]\r\e[0KInstalling common packages"
-      - apt-get install make git ccache
+      - apt-get install make git ccache libsimde-dev
       - |
           # apt_common
           echo -e "\e[0Ksection_end:`date +%s`:apt_common\r\e[0K"
@@ -219,6 +219,7 @@ i386:
   variables:
     CC: ccache i686-linux-gnu-gcc
     CXX: ccache i686-linux-gnu-g++
+    CPPFLAGS: -msse2 -U NO_SSE
 
   artifacts:
     paths:
@@ -343,6 +344,8 @@ win32:
   variables:
     CC: ccache i686-w64-mingw32-gcc-posix
     CXX: ccache i686-w64-mingw32-g++-posix
+    CFLAGS: -Wall -Wextra -Werror
+    CXXFLAGS: -Wall -Wextra -Werror -Wno-unused-parameter
 
   artifacts:
     paths:
@@ -376,6 +379,8 @@ win64:
   variables:
     CC: ccache x86_64-w64-mingw32-gcc-posix
     CXX: ccache x86_64-w64-mingw32-g++-posix
+    CFLAGS: -Wall -Wextra -Werror
+    CXXFLAGS: -Wall -Wextra -Werror -Wno-unused-parameter
 
   artifacts:
     paths:
diff --git a/Makefile b/Makefile
index 0af6d3ae..f7543c5f 100644
--- a/Makefile
+++ b/Makefile
@@ -23,6 +23,10 @@ CPPFLAGS_ := $(INC_FLAGS) -MMD -MP
 
 CFLAGS_ = -O2 -g3 -fPIC
 
+ifdef MINGW
+CFLAGS_ += -msse2
+endif
+
 CXXFLAGS_ = -std=c++14 $(CFLAGS_)
 
 ifdef MINGW
diff --git a/Source/Native/OpenGL/OpenGLContext.cpp b/Source/Native/OpenGL/OpenGLContext.cpp
index 4e2d7ec9..5781dc2d 100644
--- a/Source/Native/OpenGL/OpenGLContext.cpp
+++ b/Source/Native/OpenGL/OpenGLContext.cpp
@@ -178,14 +178,14 @@ void OpenGLContext::SwapBuffers()
 
 int OpenGLContext::GetWidth() const
 {
-	RECT box = { 0 };
+	RECT box = { 0, 0, 0, 0 };
 	GetClientRect(window, &box);
 	return box.right - box.left;
 }
 
 int OpenGLContext::GetHeight() const
 {
-	RECT box = { 0 };
+	RECT box = { 0, 0, 0, 0 };
 	GetClientRect(window, &box);
 	return box.bottom - box.top;
 }
@@ -217,10 +217,10 @@ OpenGLContext::CreateFunctions OpenGLContext::GetCreateFunctions(HWND window)
 			{
 				wglMakeCurrent(queryDC, queryContext);
 
-				functions.wglCreateContextAttribsARB = (ptr_wglCreateContextAttribsARB)wglGetProcAddress("wglCreateContextAttribsARB");
-				functions.wglGetPixelFormatAttribivEXT = (ptr_wglGetPixelFormatAttribivEXT)wglGetProcAddress("wglGetPixelFormatAttribivEXT");
-				functions.wglGetPixelFormatAttribfvEXT = (ptr_wglGetPixelFormatAttribfvEXT)wglGetProcAddress("wglGetPixelFormatAttribfvEXT");
-				functions.wglChoosePixelFormatEXT = (ptr_wglChoosePixelFormatEXT)wglGetProcAddress("wglChoosePixelFormatEXT");
+				functions.wglCreateContextAttribsARB = (ptr_wglCreateContextAttribsARB)(void*)wglGetProcAddress("wglCreateContextAttribsARB");
+				functions.wglGetPixelFormatAttribivEXT = (ptr_wglGetPixelFormatAttribivEXT)(void*)wglGetProcAddress("wglGetPixelFormatAttribivEXT");
+				functions.wglGetPixelFormatAttribfvEXT = (ptr_wglGetPixelFormatAttribfvEXT)(void*)wglGetProcAddress("wglGetPixelFormatAttribfvEXT");
+				functions.wglChoosePixelFormatEXT = (ptr_wglChoosePixelFormatEXT)(void*)wglGetProcAddress("wglChoosePixelFormatEXT");
 
 				HMODULE opengl32 = LoadLibrary("opengl32.dll");
 				if (opengl32)
diff --git a/Source/Native/OpenGL/gl_load/gl_load.c b/Source/Native/OpenGL/gl_load/gl_load.c
index 1a05e350..3685fab2 100644
--- a/Source/Native/OpenGL/gl_load/gl_load.c
+++ b/Source/Native/OpenGL/gl_load/gl_load.c
@@ -69,7 +69,7 @@ static int TestPointer(const PROC pTest)
 	return 1;
 }
 
-static PROC WinGetProcAddress(const char *name)
+static void *WinGetProcAddress(const char *name)
 {
 	HMODULE glMod = NULL;
 	PROC pFunc = wglGetProcAddress((LPCSTR)name);
diff --git a/Source/Native/RawMouse.cpp b/Source/Native/RawMouse.cpp
index de416cae..5cdc0b4e 100644
--- a/Source/Native/RawMouse.cpp
+++ b/Source/Native/RawMouse.cpp
@@ -105,7 +105,7 @@ LRESULT RawMouse::OnMessage(INT message, WPARAM wparam, LPARAM lparam)
 		{
 			std::vector<uint32_t> buf((size + 3) / 4);
 			result = GetRawInputData(rawinputHandle, RID_INPUT, buf.data(), &size, sizeof(RAWINPUTHEADER));
-			if (result >= 0)
+			if (result != (UINT)-1)
 			{
 				RAWINPUT* rawinput = (RAWINPUT*)buf.data();
 				if (rawinput->header.dwType == RIM_TYPEMOUSE)