diff --git a/indra/newview/app_settings/shaders/class1/effects/CASF.glsl b/indra/newview/app_settings/shaders/class1/effects/CASF.glsl
index 81d20e4c3eabe62b74828ffe236995d18a7c93ea..8e72638448877962ad1aa250a2d95c0aca031486 100644
--- a/indra/newview/app_settings/shaders/class1/effects/CASF.glsl
+++ b/indra/newview/app_settings/shaders/class1/effects/CASF.glsl
@@ -23,6 +23,9 @@
  * $/LicenseInfo$
  */
 
+#extension GL_ARB_shader_texture_lod : enable
+#extension GL_EXT_gpu_shader4 : enable
+
 /*[EXTRA_CODE_HERE]*/
 
 #ifdef DEFINE_GL_FRAGCOLOR