diff --git a/src/mesa/state_tracker/st_extensions.c b/src/mesa/state_tracker/st_extensions.c
index 2c2e10dead7..8204fefc4c6 100644
--- a/src/mesa/state_tracker/st_extensions.c
+++ b/src/mesa/state_tracker/st_extensions.c
@@ -219,6 +219,8 @@ void st_init_extensions(struct st_context *st)
 
    ctx->Extensions.APPLE_vertex_array_object = GL_TRUE;
 
+   ctx->Extensions.ATI_texture_env_combine3 = GL_TRUE;
+
    ctx->Extensions.MESA_pack_invert = GL_TRUE;
 
    ctx->Extensions.NV_blend_square = GL_TRUE;