diff --git a/src/camera.cpp b/src/camera.cpp
index 032df4d..b229248 100644
--- a/src/camera.cpp
+++ b/src/camera.cpp
@@ -13,7 +13,7 @@ Camera::Camera()
 void Camera::prepare()
 {
 	// Set projection matrix
-	State::projection_matrix_ = projection_;
+	state::projection_matrix = projection_;
 
 	// Calculate view matrix
 	// For a camera, we need the inverse transformation:
@@ -29,7 +29,7 @@ void Camera::prepare()
 	// Inverse translation (translate in opposite direction)
 	view = glm::translate(view, -position_);
 
-	State::view_matrix_ = view;
+	state::view_matrix = view;
 
 	// Set viewport
 	glViewport(viewport_.x, viewport_.y, viewport_.z, viewport_.w);
diff --git a/src/engine.cpp b/src/engine.cpp
index 93593b0..3a2a9d0 100644
--- a/src/engine.cpp
+++ b/src/engine.cpp
@@ -75,11 +75,11 @@ void Engine::initialize()
 	}
 
 	// Initialize default shader
-	State::default_shader_ =
+	state::default_shader =
 	    std::make_shared<Shader>("data/vertex.glsl", "data/fragment.glsl");
-	if (std::strlen(State::default_shader_->error()) > 0) {
+	if (std::strlen(state::default_shader->error()) > 0) {
 		std::cerr << "Failed to initialize shaders: "
-			  << State::default_shader_->error() << "\n";
+			  << state::default_shader->error() << "\n";
 	}
 }
 
diff --git a/src/engine.h b/src/engine.h
index 59f07a7..80de442 100644
--- a/src/engine.h
+++ b/src/engine.h
@@ -4,6 +4,7 @@
 #include <memory>
 #include <vector>
 
+#include "../lib/glew/GL/glew.h"
 #include "../lib/glfw/glfw3.h"
 
 class World;
diff --git a/src/mesh.cpp b/src/mesh.cpp
index b5f6be5..24aa05e 100644
--- a/src/mesh.cpp
+++ b/src/mesh.cpp
@@ -13,15 +13,15 @@ void Mesh::add_buffer(const std::shared_ptr<Buffer>& buffer,
 void Mesh::draw()
 {
 	// Calculate MVP matrix
-	glm::mat4 mvp = State::projection_matrix_ * State::view_matrix_
-	    * State::model_matrix_;
+	glm::mat4 mvp = state::projection_matrix * state::view_matrix
+	    * state::model_matrix;
 
 	// Draw each buffer with its shader
 	for (size_t i = 0; i < buffers_.size(); ++i) {
 		// Use buffer's shader if available, otherwise use default
 		// shader
 		std::shared_ptr<Shader> shader =
-		    shaders_[i] ? shaders_[i] : State::default_shader_;
+		    shaders_[i] ? shaders_[i] : state::default_shader;
 
 		if (shader) {
 			shader->use();
diff --git a/src/model.cpp b/src/model.cpp
index e5c631d..73afc0e 100644
--- a/src/model.cpp
+++ b/src/model.cpp
@@ -27,8 +27,8 @@ void Model::draw()
 	// Scale
 	model = glm::scale(model, scale_);
 
-	// Set the model matrix in State
-	State::model_matrix_ = model;
+	// Set the model matrix in state
+	state::model_matrix = model;
 
 	// Draw the mesh
 	mesh_->draw();
diff --git a/src/state.cpp b/src/state.cpp
deleted file mode 100644
index 744f11a..0000000
--- a/src/state.cpp
+++ /dev/null
@@ -1,6 +0,0 @@
-#include "state.h"
-
-std::shared_ptr<Shader> State::default_shader_	  = nullptr;
-glm::mat4		State::projection_matrix_ = glm::mat4(1.0f);
-glm::mat4		State::view_matrix_	  = glm::mat4(1.0f);
-glm::mat4		State::model_matrix_	  = glm::mat4(1.0f);
diff --git a/src/state.h b/src/state.h
index bd24ae7..c611ba6 100644
--- a/src/state.h
+++ b/src/state.h
@@ -6,12 +6,13 @@
 
 class Shader;
 
-class State {
-public:
-	static std::shared_ptr<Shader> default_shader_;
-	static glm::mat4	       projection_matrix_;
-	static glm::mat4	       view_matrix_;
-	static glm::mat4	       model_matrix_;
-};
+namespace state {
+
+inline std::shared_ptr<Shader> default_shader	 = nullptr;
+inline glm::mat4	       projection_matrix = glm::mat4(1.0f);
+inline glm::mat4	       view_matrix	 = glm::mat4(1.0f);
+inline glm::mat4	       model_matrix	 = glm::mat4(1.0f);
+
+} // namespace state
 
 #endif // STATE_H_
diff --git a/ugine3d.vcxproj b/ugine3d.vcxproj
index 6021d72..702a68d 100644
--- a/ugine3d.vcxproj
+++ b/ugine3d.vcxproj
@@ -180,7 +180,6 @@
     <ClCompile Include="src\mesh.cpp" />
     <ClCompile Include="src\model.cpp" />
     <ClCompile Include="src\shader.cpp" />
-    <ClCompile Include="src\state.cpp" />
     <ClCompile Include="src\vertex.cpp" />
     <ClCompile Include="src\world.cpp" />
   </ItemGroup>
diff --git a/ugine3d.vcxproj.filters b/ugine3d.vcxproj.filters
index 290bd8b..39837d9 100644
--- a/ugine3d.vcxproj.filters
+++ b/ugine3d.vcxproj.filters
@@ -80,9 +80,6 @@
     <ClCompile Include="src\buffer.cpp">
       <Filter>Source Files</Filter>
     </ClCompile>
-    <ClCompile Include="src\state.cpp">
-      <Filter>Source Files</Filter>
-    </ClCompile>
     <ClCompile Include="src\mesh.cpp">
       <Filter>Source Files</Filter>
     </ClCompile>