diff --git a/src/mesh_viewer.cpp b/src/mesh_viewer.cpp
index c648a60..66c3b9c 100644
--- a/src/mesh_viewer.cpp
+++ b/src/mesh_viewer.cpp
@@ -5,12 +5,10 @@
 
 
 const GLchar *vertex_shader_source = R"glsl(
-#version 150 core
+attribute vec3 pos;
+attribute vec3 col;
 
-in vec3 pos;
-in vec3 col;
-
-out vec3 frag_col;
+varying vec3 frag_col;
 
 uniform mat4 proj;
 uniform mat4 view;
@@ -23,10 +21,7 @@ void main() {
 )glsl";
 
 const GLchar *fragment_shader_source = R"glsl(
-#version 150 core
-
-in vec3 frag_col;
-out vec4 final_col;
+varying vec3 frag_col;
 
 uniform vec3 wf_col;
 uniform bool wireframe;
@@ -34,9 +29,9 @@ uniform float alpha;
 
 void main() {
 	if (wireframe)
-		final_col = vec4(wf_col, alpha);
+		gl_FragColor = vec4(wf_col, alpha);
 	else
-		final_col = vec4(frag_col, alpha);
+		gl_FragColor = vec4(frag_col, alpha);
 }
 )glsl";