diff --git a/res/org/lwjgl/demo/opengl/shader/raymarching.fs.glsl b/res/org/lwjgl/demo/opengl/shader/raymarching.fs.glsl
index 922288e3..c213c4d8 100644
--- a/res/org/lwjgl/demo/opengl/shader/raymarching.fs.glsl
+++ b/res/org/lwjgl/demo/opengl/shader/raymarching.fs.glsl
@@ -5,6 +5,10 @@
 #version 330 core
 
 layout (location = 0) out vec4 fragColor;
+#ifdef GL_ARB_conservative_depth
+#extension GL_ARB_conservative_depth : enable
+layout (depth_less) out float gl_FragDepth;
+#endif
 
 uniform sampler3D tex;
 uniform mat4 mvp;