diff --git a/src/compiler/glsl/ir_optimization.h b/src/compiler/glsl/ir_optimization.h
index b64e5c7363a..56e5cebb706 100644
--- a/src/compiler/glsl/ir_optimization.h
+++ b/src/compiler/glsl/ir_optimization.h
@@ -120,7 +120,6 @@ bool do_function_inlining(exec_list *instructions);
 bool do_lower_jumps(exec_list *instructions, bool pull_out_jumps = true, bool lower_sub_return = true, bool lower_main_return = false, bool lower_continue = false, bool lower_break = false);
 bool do_if_simplification(exec_list *instructions);
 bool opt_flatten_nested_if_blocks(exec_list *instructions);
-bool do_discard_simplification(exec_list *instructions);
 bool lower_if_to_cond_assign(gl_shader_stage stage, exec_list *instructions,
                              unsigned max_depth = 0, unsigned min_branch_cost = 0);
 bool do_mat_op_to_vec(exec_list *instructions);