diff --git a/src/compiler/nir/nir_dominance.c b/src/compiler/nir/nir_dominance.c
index 14d3e1578c5..dc6726f130f 100644
--- a/src/compiler/nir/nir_dominance.c
+++ b/src/compiler/nir/nir_dominance.c
@@ -135,6 +135,10 @@ calc_dom_children(nir_function_impl *impl)
    }
 
    nir_foreach_block_unstructured(block, impl) {
+      if (!block->num_dom_children) {
+         block->dom_children = NULL;
+         continue;
+      }
       block->dom_children = ralloc_array(mem_ctx, nir_block *,
                                          block->num_dom_children);
       block->num_dom_children = 0;