diff --git a/src/core.c b/src/core.c
index d27a031b8..c8d781337 100644
--- a/src/core.c
+++ b/src/core.c
@@ -1488,11 +1488,11 @@ static void InitDisplay(int width, int height)
         TraceLog(INFO, "Viewport offsets: %i, %i", renderOffsetX, renderOffsetY);
     }
 
-    glfwSetWindowSizeCallback(window, WindowSizeCallback);
+    glfwSetWindowSizeCallback(window, WindowSizeCallback);      // NOTE: Resizing not allowed by default!
     glfwSetCursorEnterCallback(window, CursorEnterCallback);
     glfwSetKeyCallback(window, KeyCallback);
     glfwSetMouseButtonCallback(window, MouseButtonCallback);
-    glfwSetCursorPosCallback(window, MouseCursorPosCallback);    // Track mouse position changes
+    glfwSetCursorPosCallback(window, MouseCursorPosCallback);   // Track mouse position changes
     glfwSetCharCallback(window, CharCallback);
     glfwSetScrollCallback(window, ScrollCallback);
     glfwSetWindowIconifyCallback(window, WindowIconifyCallback);
@@ -1818,16 +1818,19 @@ static void CursorEnterCallback(GLFWwindow *window, int enter)
 }
 
 // GLFW3 WindowSize Callback, runs when window is resized
+// NOTE: Window resizing not allowed by default
 static void WindowSizeCallback(GLFWwindow *window, int width, int height)
 {
     // If window is resized, graphics device is re-initialized (but only ortho mode)
-    rlglInitGraphics(renderOffsetX, renderOffsetY, renderWidth, renderHeight);
+    rlglInitGraphics(0, 0, width, height);
 
     // Window size must be updated to be used on 3D mode to get new aspect ratio (Begin3dMode())
-    //screenWidth = width;
-    //screenHeight = height;
-
-    // TODO: Update render size?
+    screenWidth = width;
+    screenHeight = height;
+    renderWidth = width;
+    renderHeight = height;
+    
+    // NOTE: Postprocessing texture is not scaled to new size
 
     // Background must be also re-cleared
     ClearBackground(RAYWHITE);
diff --git a/src/rlgl.c b/src/rlgl.c
index b6a179d64..fc14a0af9 100644
--- a/src/rlgl.c
+++ b/src/rlgl.c
@@ -188,6 +188,8 @@ typedef struct {
 // Framebuffer Object type
 typedef struct {
     GLuint id;
+    int width;
+    int height;
     GLuint colorTextureId;
     GLuint depthTextureId;
 } FBO;
@@ -1071,8 +1073,8 @@ void rlglInitPostpro(void)
         
         quad.vertexCount = 6;
         
-        float w = (float)screenWidth;
-        float h = (float)screenHeight;
+        float w = (float)postproFbo.width;
+        float h = (float)postproFbo.height;
         
         float quadPositions[6*3] = { w, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, h, 0.0f, 0.0f, h, 0.0f, w, h, 0.0f, w, 0.0f, 0.0f }; 
         float quadTexcoords[6*2] = { 1.0f, 1.0f, 0.0f, 1.0f, 0.0f, 0.0f, 0.0f, 0.0f, 1.0f, 0.0f, 1.0f, 1.0f };
@@ -1096,6 +1098,8 @@ FBO rlglLoadFBO(int width, int height)
 {
     FBO fbo;   
     fbo.id = 0;
+    fbo.width = width;
+    fbo.height = height;
 
 #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_ES2)
     // Create the texture that will serve as the color attachment for the framebuffer
@@ -2339,22 +2343,21 @@ void SetCustomShader(Shader shader)
 }
 
 // Set postprocessing shader
-// NOTE: Uses global variables screenWidth and screenHeight
 void SetPostproShader(Shader shader)
 {
 #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_ES2)
     if (!enabledPostpro)
     {
         enabledPostpro = true;
-        rlglInitPostpro();
+        rlglInitPostpro();      // Lazy initialization on postprocessing usage
     }
 
     SetModelShader(&postproQuad, shader);
     
     Texture2D texture;
     texture.id = postproFbo.colorTextureId;
-    texture.width = screenWidth;
-    texture.height = screenHeight;
+    texture.width = postproFbo.width;
+    texture.height = postproFbo.height;
 
     postproQuad.material.texDiffuse = texture;