diff --git a/src/intel/compiler/brw_nir_rt.c b/src/intel/compiler/brw_nir_rt.c
index ad529cdfcce..b124928b293 100644
--- a/src/intel/compiler/brw_nir_rt.c
+++ b/src/intel/compiler/brw_nir_rt.c
@@ -489,6 +489,7 @@ brw_nir_create_raygen_trampoline(const struct brw_compiler *compiler,
 
    NIR_PASS_V(nir, brw_nir_lower_rt_intrinsics, devinfo);
 
+   nir_builder_init(&b, nir_shader_get_entrypoint(b.shader));
    /* brw_nir_lower_rt_intrinsics will leave us with a btd_global_arg_addr
     * intrinsic which doesn't exist in compute shaders.  We also created one
     * above when we generated the BTD spawn intrinsic.  Now we go through and