diff --git a/src/util/register_allocate.c b/src/util/register_allocate.c
index 83686feb62c..d9686d20534 100644
--- a/src/util/register_allocate.c
+++ b/src/util/register_allocate.c
@@ -454,6 +454,8 @@ ra_set_deserialize(void *mem_ctx, struct blob_reader *blob)
    for (unsigned int c = 0; c < class_count; c++) {
       struct ra_class *class = rzalloc(regs, struct ra_class);
       regs->classes[c] = class;
+      class->regset = regs;
+      class->index = c;
 
       class->regs = ralloc_array(class, BITSET_WORD, BITSET_WORDS(reg_count));
       blob_copy_bytes(blob, class->regs, BITSET_WORDS(reg_count) *
diff --git a/src/util/tests/register_allocate_test.cpp b/src/util/tests/register_allocate_test.cpp
index de463954abf..498985e4933 100644
--- a/src/util/tests/register_allocate_test.cpp
+++ b/src/util/tests/register_allocate_test.cpp
@@ -212,7 +212,7 @@ TEST_F(ra_test, aligned_contigregs)
    }
 }
 
-TEST_F(ra_test, DISABLED_serialization_roundtrip)
+TEST_F(ra_test, serialization_roundtrip)
 {
    struct blob blob;
    blob_init(&blob);