diff --git a/internal/graphics/shader.go b/internal/graphics/shader.go
index df9daf898..962befda9 100644
--- a/internal/graphics/shader.go
+++ b/internal/graphics/shader.go
@@ -32,15 +32,15 @@ attribute vec2 vertex;
 attribute vec4 tex_coord;
 attribute vec4 geo_matrix_body;
 attribute vec2 geo_matrix_translation;
-varying vec2 vertex_out_tex_coord;
-varying vec2 vertex_out_tex_coord_min;
-varying vec2 vertex_out_tex_coord_max;
+varying vec2 varying_tex_coord;
+varying vec2 varying_tex_coord_min;
+varying vec2 varying_tex_coord_max;
 
 void main(void) {
-  vertex_out_tex_coord = vec2(tex_coord[0], tex_coord[1]);
-  vertex_out_tex_coord_min =
+  varying_tex_coord = vec2(tex_coord[0], tex_coord[1]);
+  varying_tex_coord_min =
     vec2(min(tex_coord[0], tex_coord[2]), min(tex_coord[1], tex_coord[3]));
-  vertex_out_tex_coord_max =
+  varying_tex_coord_max =
     vec2(max(tex_coord[0], tex_coord[2]), max(tex_coord[1], tex_coord[3]));
   mat4 geo_matrix = mat4(
     vec4(geo_matrix_body[0], geo_matrix_body[2], 0, 0),
@@ -63,17 +63,17 @@ precision mediump float;
 uniform sampler2D texture;
 uniform mat4 color_matrix;
 uniform vec4 color_matrix_translation;
-varying vec2 vertex_out_tex_coord;
-varying vec2 vertex_out_tex_coord_min;
-varying vec2 vertex_out_tex_coord_max;
+varying vec2 varying_tex_coord;
+varying vec2 varying_tex_coord_min;
+varying vec2 varying_tex_coord_max;
 
 void main(void) {
   vec4 color = vec4(0, 0, 0, 0);
-  if (vertex_out_tex_coord_min.x <= vertex_out_tex_coord.x &&
-      vertex_out_tex_coord_min.y <= vertex_out_tex_coord.y &&
-      vertex_out_tex_coord.x < vertex_out_tex_coord_max.x &&
-      vertex_out_tex_coord.y < vertex_out_tex_coord_max.y) {
-    color = texture2D(texture, vertex_out_tex_coord);
+  if (varying_tex_coord_min.x <= varying_tex_coord.x &&
+      varying_tex_coord_min.y <= varying_tex_coord.y &&
+      varying_tex_coord.x < varying_tex_coord_max.x &&
+      varying_tex_coord.y < varying_tex_coord_max.y) {
+    color = texture2D(texture, varying_tex_coord);
   }
 
   // Un-premultiply alpha