diff --git a/src/System/SharedLibrary.hpp b/src/System/SharedLibrary.hpp
index fc12842..a2c3d1b 100644
--- a/src/System/SharedLibrary.hpp
+++ b/src/System/SharedLibrary.hpp
@@ -133,4 +133,10 @@
 }
 #endif
 
+template<typename FunctionPointer>
+inline void getFuncAddress(void *library, const char *functionName, FunctionPointer *out)
+{
+	*out = reinterpret_cast<FunctionPointer>(getProcAddress(library, functionName));
+}
+
 #endif  // SharedLibrary_hpp
diff --git a/src/Vulkan/libVulkan.cpp b/src/Vulkan/libVulkan.cpp
index 8bf30f7..0eb0ba1 100644
--- a/src/Vulkan/libVulkan.cpp
+++ b/src/Vulkan/libVulkan.cpp
@@ -312,10 +312,10 @@
 	{ { VK_KHR_SURFACE_EXTENSION_NAME, VK_KHR_SURFACE_SPEC_VERSION } },
 #endif
 #ifdef VK_USE_PLATFORM_XCB_KHR
-	{ { VK_KHR_XCB_SURFACE_EXTENSION_NAME, VK_KHR_XCB_SURFACE_SPEC_VERSION }, [] { return vk::XcbSurfaceKHR::hasLibXCB(); } },
+	{ { VK_KHR_XCB_SURFACE_EXTENSION_NAME, VK_KHR_XCB_SURFACE_SPEC_VERSION }, [] { return vk::XcbSurfaceKHR::isSupported(); } },
 #endif
 #ifdef VK_USE_PLATFORM_XLIB_KHR
-	{ { VK_KHR_XLIB_SURFACE_EXTENSION_NAME, VK_KHR_XLIB_SURFACE_SPEC_VERSION }, [] { return static_cast<bool>(libX11); } },
+	{ { VK_KHR_XLIB_SURFACE_EXTENSION_NAME, VK_KHR_XLIB_SURFACE_SPEC_VERSION }, [] { return vk::XlibSurfaceKHR::isSupported(); } },
 #endif
 #ifdef VK_USE_PLATFORM_WAYLAND_KHR
 	{ { VK_KHR_WAYLAND_SURFACE_EXTENSION_NAME, VK_KHR_WAYLAND_SURFACE_SPEC_VERSION } },
diff --git a/src/WSI/BUILD.gn b/src/WSI/BUILD.gn
index 248ba31..22af89f 100644
--- a/src/WSI/BUILD.gn
+++ b/src/WSI/BUILD.gn
@@ -41,6 +41,8 @@
       "XlibSurfaceKHR.hpp",
       "libX11.cpp",
       "libX11.hpp",
+      "libXCB.cpp",
+      "libXCB.hpp",
     ]
   }
 
diff --git a/src/WSI/CMakeLists.txt b/src/WSI/CMakeLists.txt
index 84f5d80..4a27242 100644
--- a/src/WSI/CMakeLists.txt
+++ b/src/WSI/CMakeLists.txt
@@ -45,6 +45,8 @@
         list(APPEND WSI_SRC_FILES
             XcbSurfaceKHR.cpp
             XcbSurfaceKHR.hpp
+            libXCB.cpp
+            libXCB.hpp
         )
     endif()
 
diff --git a/src/WSI/XcbSurfaceKHR.cpp b/src/WSI/XcbSurfaceKHR.cpp
index b0fe106..4e2f4e6 100644
--- a/src/WSI/XcbSurfaceKHR.cpp
+++ b/src/WSI/XcbSurfaceKHR.cpp
@@ -14,83 +14,18 @@
 
 #include "XcbSurfaceKHR.hpp"
 
+#include "libXCB.hpp"
 #include "Vulkan/VkDeviceMemory.hpp"
 #include "Vulkan/VkImage.hpp"
 
-#include "System/SharedLibrary.hpp"
-
 #include <memory>
 
-namespace {
-
-template<typename FPTR>
-void getFuncAddress(void *lib, const char *name, FPTR *out)
-{
-	*out = reinterpret_cast<FPTR>(getProcAddress(lib, name));
-}
-
-struct LibXcbExports
-{
-	LibXcbExports(void *lib)
-	{
-		getFuncAddress(lib, "xcb_create_gc", &xcb_create_gc);
-		getFuncAddress(lib, "xcb_flush", &xcb_flush);
-		getFuncAddress(lib, "xcb_free_gc", &xcb_free_gc);
-		getFuncAddress(lib, "xcb_generate_id", &xcb_generate_id);
-		getFuncAddress(lib, "xcb_get_geometry", &xcb_get_geometry);
-		getFuncAddress(lib, "xcb_get_geometry_reply", &xcb_get_geometry_reply);
-		getFuncAddress(lib, "xcb_put_image", &xcb_put_image);
-	}
-
-	xcb_void_cookie_t (*xcb_create_gc)(xcb_connection_t *c, xcb_gcontext_t cid, xcb_drawable_t drawable, uint32_t value_mask, const void *value_list);
-	int (*xcb_flush)(xcb_connection_t *c);
-	xcb_void_cookie_t (*xcb_free_gc)(xcb_connection_t *c, xcb_gcontext_t gc);
-	uint32_t (*xcb_generate_id)(xcb_connection_t *c);
-	xcb_get_geometry_cookie_t (*xcb_get_geometry)(xcb_connection_t *c, xcb_drawable_t drawable);
-	xcb_get_geometry_reply_t *(*xcb_get_geometry_reply)(xcb_connection_t *c, xcb_get_geometry_cookie_t cookie, xcb_generic_error_t **e);
-	xcb_void_cookie_t (*xcb_put_image)(xcb_connection_t *c, uint8_t format, xcb_drawable_t drawable, xcb_gcontext_t gc, uint16_t width, uint16_t height, int16_t dst_x, int16_t dst_y, uint8_t left_pad, uint8_t depth, uint32_t data_len, const uint8_t *data);
-};
-
-class LibXcb
-{
-public:
-	operator bool()
-	{
-		return loadExports();
-	}
-
-	LibXcbExports *operator->()
-	{
-		return loadExports();
-	}
-
-private:
-	LibXcbExports *loadExports()
-	{
-		static auto exports = [] {
-			if(getProcAddress(RTLD_DEFAULT, "xcb_create_gc"))
-			{
-				return std::make_unique<LibXcbExports>(RTLD_DEFAULT);
-			}
-
-			if(auto lib = loadLibrary("libxcb.so.1"))
-			{
-				return std::make_unique<LibXcbExports>(lib);
-			}
-
-			return std::unique_ptr<LibXcbExports>();
-		}();
-
-		return exports.get();
-	}
-};
-
-LibXcb libXcb;
+namespace vk {
 
 bool getWindowSizeAndDepth(xcb_connection_t *connection, xcb_window_t window, VkExtent2D *windowExtent, int *depth)
 {
-	auto cookie = libXcb->xcb_get_geometry(connection, window);
-	if(auto *geom = libXcb->xcb_get_geometry_reply(connection, cookie, nullptr))
+	auto cookie = libXCB->xcb_get_geometry(connection, window);
+	if(auto *geom = libXCB->xcb_get_geometry_reply(connection, cookie, nullptr))
 	{
 		windowExtent->width = static_cast<uint32_t>(geom->width);
 		windowExtent->height = static_cast<uint32_t>(geom->height);
@@ -101,19 +36,16 @@
 	return false;
 }
 
-}  // anonymous namespace
-
-namespace vk {
-
-bool XcbSurfaceKHR::hasLibXCB()
+bool XcbSurfaceKHR::isSupported()
 {
-	return libXcb;
+	return libXCB.isPresent();
 }
 
 XcbSurfaceKHR::XcbSurfaceKHR(const VkXcbSurfaceCreateInfoKHR *pCreateInfo, void *mem)
     : connection(pCreateInfo->connection)
     , window(pCreateInfo->window)
 {
+	ASSERT(isSupported());
 }
 
 void XcbSurfaceKHR::destroySurface(const VkAllocationCallbacks *pAllocator)
@@ -144,10 +76,10 @@
 
 void XcbSurfaceKHR::attachImage(PresentImage *image)
 {
-	auto gc = libXcb->xcb_generate_id(connection);
+	auto gc = libXCB->xcb_generate_id(connection);
 
 	uint32_t values[2] = { 0, 0xffffffff };
-	libXcb->xcb_create_gc(connection, gc, window, XCB_GC_FOREGROUND | XCB_GC_BACKGROUND, values);
+	libXCB->xcb_create_gc(connection, gc, window, XCB_GC_FOREGROUND | XCB_GC_BACKGROUND, values);
 
 	graphicsContexts[image] = gc;
 }
@@ -157,7 +89,7 @@
 	auto it = graphicsContexts.find(image);
 	if(it != graphicsContexts.end())
 	{
-		libXcb->xcb_free_gc(connection, it->second);
+		libXCB->xcb_free_gc(connection, it->second);
 		graphicsContexts.erase(it);
 	}
 }
@@ -185,7 +117,7 @@
 		int stride = image->getImage()->rowPitchBytes(VK_IMAGE_ASPECT_COLOR_BIT, 0);
 		auto buffer = reinterpret_cast<uint8_t *>(image->getImageMemory()->getOffsetPointer(0));
 		size_t bufferSize = extent.height * stride;
-		libXcb->xcb_put_image(
+		libXCB->xcb_put_image(
 		    connection,
 		    XCB_IMAGE_FORMAT_Z_PIXMAP,
 		    window,
@@ -199,7 +131,7 @@
 		    buffer       // data
 		);
 
-		libXcb->xcb_flush(connection);
+		libXCB->xcb_flush(connection);
 	}
 
 	return VK_SUCCESS;
diff --git a/src/WSI/XcbSurfaceKHR.hpp b/src/WSI/XcbSurfaceKHR.hpp
index 91c1d7e..4f2ee8b 100644
--- a/src/WSI/XcbSurfaceKHR.hpp
+++ b/src/WSI/XcbSurfaceKHR.hpp
@@ -28,6 +28,7 @@
 class XcbSurfaceKHR : public SurfaceKHR, public ObjectBase<XcbSurfaceKHR, VkSurfaceKHR>
 {
 public:
+	static bool isSupported();
 	XcbSurfaceKHR(const VkXcbSurfaceCreateInfoKHR *pCreateInfo, void *mem);
 
 	void destroySurface(const VkAllocationCallbacks *pAllocator) override;
@@ -40,8 +41,6 @@
 	virtual void detachImage(PresentImage *image) override;
 	VkResult present(PresentImage *image) override;
 
-	static bool hasLibXCB();
-
 private:
 	xcb_connection_t *connection;
 	xcb_window_t window;
diff --git a/src/WSI/XlibSurfaceKHR.cpp b/src/WSI/XlibSurfaceKHR.cpp
index 7885180..881f436 100644
--- a/src/WSI/XlibSurfaceKHR.cpp
+++ b/src/WSI/XlibSurfaceKHR.cpp
@@ -19,10 +19,17 @@
 
 namespace vk {
 
+bool XlibSurfaceKHR::isSupported()
+{
+	return libX11.isPresent();
+}
+
 XlibSurfaceKHR::XlibSurfaceKHR(const VkXlibSurfaceCreateInfoKHR *pCreateInfo, void *mem)
     : pDisplay(pCreateInfo->dpy)
     , window(pCreateInfo->window)
 {
+	ASSERT(isSupported());
+
 	int screen = DefaultScreen(pDisplay);
 	gc = libX11->XDefaultGC(pDisplay, screen);
 
diff --git a/src/WSI/XlibSurfaceKHR.hpp b/src/WSI/XlibSurfaceKHR.hpp
index fbba62a..a0e6aba 100644
--- a/src/WSI/XlibSurfaceKHR.hpp
+++ b/src/WSI/XlibSurfaceKHR.hpp
@@ -28,6 +28,7 @@
 class XlibSurfaceKHR : public SurfaceKHR, public ObjectBase<XlibSurfaceKHR, VkSurfaceKHR>
 {
 public:
+	static bool isSupported();
 	XlibSurfaceKHR(const VkXlibSurfaceCreateInfoKHR *pCreateInfo, void *mem);
 
 	void destroySurface(const VkAllocationCallbacks *pAllocator) override;
diff --git a/src/WSI/libX11.cpp b/src/WSI/libX11.cpp
index 72d9fdb..5d72c4f 100644
--- a/src/WSI/libX11.cpp
+++ b/src/WSI/libX11.cpp
@@ -15,18 +15,9 @@
 #include "libX11.hpp"
 
 #include "System/SharedLibrary.hpp"
+
 #include <memory>
 
-namespace {
-
-template<typename FPTR>
-void getFuncAddress(void *lib, const char *name, FPTR *out)
-{
-	*out = reinterpret_cast<FPTR>(getProcAddress(lib, name));
-}
-
-}  // anonymous namespace
-
 LibX11exports::LibX11exports(void *libX11, void *libXext)
 {
 	getFuncAddress(libX11, "XOpenDisplay", &XOpenDisplay);
diff --git a/src/WSI/libX11.hpp b/src/WSI/libX11.hpp
index 65fe593..b40bc6c 100644
--- a/src/WSI/libX11.hpp
+++ b/src/WSI/libX11.hpp
@@ -52,9 +52,9 @@
 class LibX11
 {
 public:
-	operator bool()
+	bool isPresent()
 	{
-		return loadExports();
+		return loadExports() != nullptr;
 	}
 
 	LibX11exports *operator->();
diff --git a/src/WSI/libXCB.cpp b/src/WSI/libXCB.cpp
new file mode 100644
index 0000000..c540cb8
--- /dev/null
+++ b/src/WSI/libXCB.cpp
@@ -0,0 +1,56 @@
+// Copyright 2021 The SwiftShader Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "libXCB.hpp"
+
+#include "System/SharedLibrary.hpp"
+
+#include <memory>
+
+LibXcbExports::LibXcbExports(void *lib)
+{
+	getFuncAddress(lib, "xcb_create_gc", &xcb_create_gc);
+	getFuncAddress(lib, "xcb_flush", &xcb_flush);
+	getFuncAddress(lib, "xcb_free_gc", &xcb_free_gc);
+	getFuncAddress(lib, "xcb_generate_id", &xcb_generate_id);
+	getFuncAddress(lib, "xcb_get_geometry", &xcb_get_geometry);
+	getFuncAddress(lib, "xcb_get_geometry_reply", &xcb_get_geometry_reply);
+	getFuncAddress(lib, "xcb_put_image", &xcb_put_image);
+}
+
+LibXcbExports *LibXCB::operator->()
+{
+	return loadExports();
+}
+
+LibXcbExports *LibXCB::loadExports()
+{
+	static auto exports = [] {
+		if(getProcAddress(RTLD_DEFAULT, "xcb_create_gc"))
+		{
+			return std::make_unique<LibXcbExports>(RTLD_DEFAULT);
+		}
+
+		if(void *lib = loadLibrary("libxcb.so.1"))
+		{
+			return std::make_unique<LibXcbExports>(lib);
+		}
+
+		return std::unique_ptr<LibXcbExports>();
+	}();
+
+	return exports.get();
+}
+
+LibXCB libXCB;
diff --git a/src/WSI/libXCB.hpp b/src/WSI/libXCB.hpp
new file mode 100644
index 0000000..1e535cb
--- /dev/null
+++ b/src/WSI/libXCB.hpp
@@ -0,0 +1,49 @@
+// Copyright 2021 The SwiftShader Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef libXCB_hpp
+#define libXCB_hpp
+
+#include <xcb/xcb.h>
+
+struct LibXcbExports
+{
+	LibXcbExports(void *lib);
+
+	xcb_void_cookie_t (*xcb_create_gc)(xcb_connection_t *c, xcb_gcontext_t cid, xcb_drawable_t drawable, uint32_t value_mask, const void *value_list);
+	int (*xcb_flush)(xcb_connection_t *c);
+	xcb_void_cookie_t (*xcb_free_gc)(xcb_connection_t *c, xcb_gcontext_t gc);
+	uint32_t (*xcb_generate_id)(xcb_connection_t *c);
+	xcb_get_geometry_cookie_t (*xcb_get_geometry)(xcb_connection_t *c, xcb_drawable_t drawable);
+	xcb_get_geometry_reply_t *(*xcb_get_geometry_reply)(xcb_connection_t *c, xcb_get_geometry_cookie_t cookie, xcb_generic_error_t **e);
+	xcb_void_cookie_t (*xcb_put_image)(xcb_connection_t *c, uint8_t format, xcb_drawable_t drawable, xcb_gcontext_t gc, uint16_t width, uint16_t height, int16_t dst_x, int16_t dst_y, uint8_t left_pad, uint8_t depth, uint32_t data_len, const uint8_t *data);
+};
+
+class LibXCB
+{
+public:
+	bool isPresent()
+	{
+		return loadExports() != nullptr;
+	}
+
+	LibXcbExports *operator->();
+
+private:
+	LibXcbExports *loadExports();
+};
+
+extern LibXCB libXCB;
+
+#endif  // libXCB_hpp