diff --git a/src/gallium/drivers/r600/sfn/sfn_nir_lower_fs_out_to_vector.cpp b/src/gallium/drivers/r600/sfn/sfn_nir_lower_fs_out_to_vector.cpp
index 4441a47dfce..818c1f22566 100644
--- a/src/gallium/drivers/r600/sfn/sfn_nir_lower_fs_out_to_vector.cpp
+++ b/src/gallium/drivers/r600/sfn/sfn_nir_lower_fs_out_to_vector.cpp
@@ -42,7 +42,7 @@ using std::vector;
 using std::array;
 
 struct nir_intrinsic_instr_less  {
-   bool operator () (const nir_intrinsic_instr *lhs, const nir_intrinsic_instr *rhs)
+   bool operator () (const nir_intrinsic_instr *lhs, const nir_intrinsic_instr *rhs) const
    {
       nir_variable *vlhs = nir_deref_instr_get_variable(nir_src_as_deref(lhs->src[0]));
       nir_variable *vrhs = nir_deref_instr_get_variable(nir_src_as_deref(rhs->src[0]));