diff --git a/src/Window.cc b/src/Window.cc
index 7eafe8d..18e4b7c 100644
--- a/src/Window.cc
+++ b/src/Window.cc
@@ -105,6 +105,11 @@ static void resize()
     Data_Get_Struct(window_instance, Window, window);
     SDL_GetWindowSize(window->sdl_window, &viewport_size[0], &viewport_size[1]);
     glViewport(0, 0, viewport_size[0], viewport_size[1]);
+    for (int i = 0; i < PROGRAM_COUNT; i++)
+    {
+        glUseProgram(window->programs[i]->id);
+        glUniform2iv(window->programs[i]->uniforms[UNIFORM_VIEWPORT_SIZE], 1, &viewport_size[0]);
+    }
     rb_funcall(window_instance,
                rb_intern("resize"),
                4,