diff --git a/src/codegen.cpp b/src/codegen.cpp
index 3e0457972cafe..4b611c9a26af9 100644
--- a/src/codegen.cpp
+++ b/src/codegen.cpp
@@ -6424,8 +6424,11 @@ static std::pair<std::unique_ptr<Module>, jl_llvm_functions_t>
             Type *vtype = julia_type_to_llvm(ctx, jt, &isboxed);
             assert(!isboxed);
             assert(!type_is_ghost(vtype) && "constants should already be handled");
-            // CreateAlloca is OK during prologue setup
-            Value *lv = ctx.builder.CreateAlloca(vtype, NULL, jl_symbol_name(s));
+            Value *lv = new AllocaInst(vtype, 0, jl_symbol_name(s), /*InsertBefore*/ctx.pgcstack);
+            if (CountTrackedPointers(vtype).count) {
+                StoreInst *SI = new StoreInst(Constant::getNullValue(vtype), lv, false, Align(sizeof(void*)));
+                SI->insertAfter(ctx.pgcstack);
+            }
             varinfo.value = mark_julia_slot(lv, jt, NULL, tbaa_stack);
             alloc_def_flag(ctx, varinfo);
             if (ctx.debug_enabled && varinfo.dinfo) {