diff --git a/src/hello.cpp b/src/hello.cpp
index 648153b..c9cd849 100644
--- a/src/hello.cpp
+++ b/src/hello.cpp
@@ -49,6 +49,10 @@
 #include <cmath>
 #include "astro/twoBodyMethods.hpp"
 
+const int WIDTH = 640;
+const int HEIGHT = 480;
+const float ASPECT = (float)WIDTH / (float)HEIGHT;
+
 // Initialize GLFW, OpenGL and GLEW, open a window and make it the current context.
 // Returns 0 for success, and -1 for any failure.
 // Failures are printed to STDERR.
@@ -64,7 +68,7 @@ int initGraphics(GLFWwindow** window)
     glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
     glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
 
-    *window = glfwCreateWindow(640, 480, "Hello Astro", NULL, NULL);
+    *window = glfwCreateWindow(WIDTH, HEIGHT, "Hello Astro", NULL, NULL);
     if (!window)
     {
         glfwTerminate();
@@ -98,8 +102,7 @@ GLint getShaderUniformLocation(GLuint shaderProgram, const std::string& uniformN
 
 void updateProjectionMatrix(GLuint shaderProgram)
 {
-    // Calculate matrices
-    float left = -1.0, right = 1.0, bottom = -1.0, top = 1.0, near = -1.0, far = 1.0;
+    float left = -ASPECT, right = ASPECT, bottom = -1.0, top = 1.0, near = -1.0, far = 1.0;
     glm::mat4 projection = glm::ortho(left, right, bottom, top, near, far);
     GLint projectionLocation = getShaderUniformLocation(shaderProgram, "_Projection");
     glUniformMatrix4fv(projectionLocation, 1, GL_FALSE, &projection[0][0]);