diff --git a/src/compiler/nir/nir_phi_builder.c b/src/compiler/nir/nir_phi_builder.c
index 6b4b6939917..acfc771da2f 100644
--- a/src/compiler/nir/nir_phi_builder.c
+++ b/src/compiler/nir/nir_phi_builder.c
@@ -216,7 +216,7 @@ nir_phi_builder_value_get_block_def(struct nir_phi_builder_value *val,
                         val->bit_size, NULL);
       phi->instr.block = dom;
       exec_list_push_tail(&val->phis, &phi->instr.node);
-      def = &phi->dest.ssa;
+      def = val->defs[dom->index] = &phi->dest.ssa;
    } else {
       /* In this case, we have an actual SSA def.  It's either the result of a
        * phi node created by the case above or one passed to us through