diff --git a/src/codegen.cpp b/src/codegen.cpp
index 53a278d42d102..f1e89e760aa1c 100644
--- a/src/codegen.cpp
+++ b/src/codegen.cpp
@@ -5031,7 +5031,7 @@ static void emit_phinode_assign(jl_codectx_t &ctx, ssize_t idx, jl_value_t *r)
             Value *ptr = ctx.builder.CreateSelect(isboxed,
                 maybe_bitcast(ctx, decay_derived(ctx, ptr_phi), getInt8PtrTy(ctx.builder.getContext())),
                 maybe_bitcast(ctx, decay_derived(ctx, phi), getInt8PtrTy(ctx.builder.getContext())));
-            jl_cgval_t val = mark_julia_slot(ptr, phiType, Tindex_phi, ctx.tbaa().tbaa_stack); // XXX: this TBAA is wrong for ptr_phi
+            jl_cgval_t val = mark_julia_slot(ptr, phiType, Tindex_phi, best_tbaa(ctx.tbaa(), phiType));
             val.Vboxed = ptr_phi;
             ctx.PhiNodes.push_back(std::make_tuple(val, BB, dest, ptr_phi, r));
             ctx.SAvalues.at(idx) = val;