diff --git a/reftable/generic.c b/reftable/generic.c
index b27d152e89..57f8032db9 100644
--- a/reftable/generic.c
+++ b/reftable/generic.c
@@ -130,7 +130,9 @@ int reftable_iterator_next_ref(struct reftable_iterator *it,
 {
 	struct reftable_record rec = {
 		.type = BLOCK_TYPE_REF,
-		.u.ref = *ref,
+		.u = {
+			.ref = *ref
+		},
 	};
 	int err = iterator_next(it, &rec);
 	*ref = rec.u.ref;
@@ -142,7 +144,9 @@ int reftable_iterator_next_log(struct reftable_iterator *it,
 {
 	struct reftable_record rec = {
 		.type = BLOCK_TYPE_LOG,
-		.u.log = *log,
+		.u = {
+			.log = *log,
+		},
 	};
 	int err = iterator_next(it, &rec);
 	*log = rec.u.log;
diff --git a/reftable/record_test.c b/reftable/record_test.c
index f91ea5e883..70ae78feca 100644
--- a/reftable/record_test.c
+++ b/reftable/record_test.c
@@ -339,7 +339,9 @@ static void test_reftable_obj_record_roundtrip(void)
 		};
 		struct reftable_record in = {
 			.type = BLOCK_TYPE_OBJ,
-			.u.obj = recs[i],
+			.u = {
+				.obj = recs[i],
+			},
 		};
 		struct strbuf key = STRBUF_INIT;
 		struct reftable_record out = { .type = BLOCK_TYPE_OBJ };
diff --git a/reftable/writer.c b/reftable/writer.c
index 6d979e245f..427f1317c6 100644
--- a/reftable/writer.c
+++ b/reftable/writer.c
@@ -257,7 +257,9 @@ int reftable_writer_add_ref(struct reftable_writer *w,
 {
 	struct reftable_record rec = {
 		.type = BLOCK_TYPE_REF,
-		.u.ref = *ref,
+		.u = {
+			.ref = *ref
+		},
 	};
 	int err = 0;
 
@@ -308,7 +310,9 @@ static int reftable_writer_add_log_verbatim(struct reftable_writer *w,
 {
 	struct reftable_record rec = {
 		.type = BLOCK_TYPE_LOG,
-		.u.log = *log,
+		.u = {
+			.log = *log,
+		},
 	};
 	if (w->block_writer &&
 	    block_writer_type(w->block_writer) == BLOCK_TYPE_REF) {
@@ -401,7 +405,9 @@ static int writer_finish_section(struct reftable_writer *w)
 		for (i = 0; i < idx_len; i++) {
 			struct reftable_record rec = {
 				.type = BLOCK_TYPE_INDEX,
-				.u.idx = idx[i],
+				.u = {
+					.idx = idx[i],
+				},
 			};
 			if (block_writer_add(w->block_writer, &rec) == 0) {
 				continue;