diff --git a/src/adb.c b/src/adb.c
index 6e63231..f1a4937 100644
--- a/src/adb.c
+++ b/src/adb.c
@@ -672,6 +672,18 @@ adb_val_t adb_w_blob(struct adb *db, apk_blob_t b)
 	return ADB_VAL(o, adb_w_data(db, vec, ARRAY_SIZE(vec), vec[0].iov_len));
 }
 
+static adb_val_t adb_w_blob_raw(struct adb *db, apk_blob_t b)
+{
+	adb_val_t val;
+	size_t num_buckets;
+
+	num_buckets = db->num_buckets;
+	db->num_buckets = 0;
+	val = adb_w_blob(db, b);
+	db->num_buckets = num_buckets;
+	return val;
+}
+
 adb_val_t adb_w_int(struct adb *db, uint32_t val)
 {
 	if (val >= 0x10000000)
@@ -869,6 +881,12 @@ adb_val_t adb_wo_blob(struct adb_obj *o, unsigned i, apk_blob_t b)
 	return adb_wo_val(o, i, adb_w_blob(o->db, b));
 }
 
+adb_val_t adb_wo_blob_raw(struct adb_obj *o, unsigned i, apk_blob_t b)
+{
+	assert(o->schema->kind == ADB_KIND_OBJECT);
+	return adb_wo_val(o, i, adb_w_blob_raw(o->db, b));
+}
+
 adb_val_t adb_wo_obj(struct adb_obj *o, unsigned i, struct adb_obj *no)
 {
 	assert(o->schema->kind == ADB_KIND_OBJECT);
diff --git a/src/adb.h b/src/adb.h
index 3dfd64c..a306d05 100644
--- a/src/adb.h
+++ b/src/adb.h
@@ -218,6 +218,7 @@ adb_val_t adb_wo_val(struct adb_obj *o, unsigned i, adb_val_t);
 adb_val_t adb_wo_val_fromstring(struct adb_obj *o, unsigned i, apk_blob_t);
 adb_val_t adb_wo_int(struct adb_obj *o, unsigned i, uint32_t);
 adb_val_t adb_wo_blob(struct adb_obj *o, unsigned i, apk_blob_t);
+adb_val_t adb_wo_blob_raw(struct adb_obj *o, unsigned i, apk_blob_t);
 adb_val_t adb_wo_obj(struct adb_obj *o, unsigned i, struct adb_obj *);
 adb_val_t adb_wo_arr(struct adb_obj *o, unsigned i, struct adb_obj *);
 adb_val_t adb_wa_append(struct adb_obj *o, adb_val_t);
diff --git a/src/apk_adb.c b/src/apk_adb.c
index 8a887cf..f8b0fe6 100644
--- a/src/apk_adb.c
+++ b/src/apk_adb.c
@@ -35,7 +35,7 @@ adb_val_t adb_wo_pkginfo(struct adb_obj *obj, unsigned int f, apk_blob_t val)
 	case ADBI_PI_UNIQUE_ID:
 		if (!val.ptr || val.len < 4) break;
 		apk_blob_pull_csum(&val, &csum);
-		v = adb_w_int(obj->db, get_unaligned32(csum.data) & ADB_VALUE_MASK);
+		v = adb_w_blob(obj->db, APK_BLOB_CSUM(csum));
 		break;
 	case ADBI_PI_REPO_COMMIT:
 		if (val.len < 40) break;
@@ -386,7 +386,7 @@ const struct adb_object_schema schema_pkginfo = {
 	.fields = {
 		ADB_FIELD(ADBI_PI_NAME,		"name",		scalar_string),
 		ADB_FIELD(ADBI_PI_VERSION,	"version",	scalar_version),
-		ADB_FIELD(ADBI_PI_UNIQUE_ID,	"unique-id",	scalar_int),
+		ADB_FIELD(ADBI_PI_UNIQUE_ID,	"unique-id",	scalar_hexblob),
 		ADB_FIELD(ADBI_PI_DESCRIPTION,	"description",	scalar_string),
 		ADB_FIELD(ADBI_PI_ARCH,		"arch",		scalar_string),
 		ADB_FIELD(ADBI_PI_LICENSE,	"license",	scalar_string),
diff --git a/src/app_mkpkg.c b/src/app_mkpkg.c
index 6944599..d855999 100644
--- a/src/app_mkpkg.c
+++ b/src/app_mkpkg.c
@@ -229,7 +229,10 @@ static int mkpkg_main(void *pctx, struct apk_ctx *ac, struct apk_string_array *a
 	int i, j, r;
 	struct mkpkg_ctx *ctx = pctx;
 	struct apk_ostream *os;
+	struct apk_digest d = {};
 	char outbuf[PATH_MAX];
+	const int uid_len = apk_digest_alg_len(APK_DIGEST_SHA1);
+	apk_blob_t uid = APK_BLOB_PTR_LEN((char*)d.data, uid_len);
 
 	ctx->ac = ac;
 	adb_w_init_alloca(&ctx->db, ADB_SCHEMA_PACKAGE, 40);
@@ -271,6 +274,7 @@ static int mkpkg_main(void *pctx, struct apk_ctx *ac, struct apk_string_array *a
 	}
 
 	adb_wo_int(&pkgi, ADBI_PI_INSTALLED_SIZE, ctx->installed_size);
+	adb_wo_blob(&pkgi, ADBI_PI_UNIQUE_ID, uid);
 	adb_wo_obj(&pkg, ADBI_PKG_PKGINFO, &pkgi);
 	adb_wo_obj(&pkg, ADBI_PKG_PATHS, &ctx->paths);
 	if (ctx->has_scripts) {
@@ -294,6 +298,11 @@ static int mkpkg_main(void *pctx, struct apk_ctx *ac, struct apk_string_array *a
 	adb_ro_obj(&pkg, ADBI_PKG_PKGINFO, &pkgi);
 	adb_ro_obj(&pkg, ADBI_PKG_PATHS, &ctx->paths);
 
+	// fill in unique id
+	apk_digest_calc(&d, APK_DIGEST_SHA256, ctx->db.adb.ptr, ctx->db.adb.len);
+	uid = adb_ro_blob(&pkgi, ADBI_PI_UNIQUE_ID);
+	memcpy(uid.ptr, d.data, uid.len);
+
 	if (!ctx->output) {
 		ctx->output = pkgi_filename(&pkgi, outbuf, sizeof outbuf);
 	}