diff --git a/source/tests/ftl/write_upage.c b/source/tests/ftl/write_upage.c
new file mode 100644
index 0000000..97e1351
--- /dev/null
+++ b/source/tests/ftl/write_upage.c
@@ -0,0 +1,131 @@
+#include <stdarg.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+#include <setjmp.h>
+
+#include <cmocka.h>
+
+#include <bitops.h>
+#include <flash.h>
+#include <ftl.h>
+#include <macros.h>
+
+int write_upage(struct ftl_map *map, const void *page,
+	struct ftl_page_desc *page_desc);
+
+static void test_prepare_head(void **state)
+{
+	struct ftl_map map;
+	struct ftl_page_desc page_desc;
+	int ret;
+
+	(void)state;
+
+	map.log2_page_size = ilog2(4 * KIB);
+	map.head = 0;
+
+	will_return(__wrap_prepare_head, -1);
+
+	ret = write_upage(&map, NULL, &page_desc);
+
+	assert_int_equal(ret, -1);
+}
+
+static void test_null_page(void **state)
+{
+	struct ftl_map map;
+	struct ftl_page_desc page_desc;
+	int ret;
+
+	(void)state;
+
+	map.log2_page_size = ilog2(4 * KIB);
+	map.head = 0;
+
+	will_return(__wrap_prepare_head, 0);
+
+	expect_value(__wrap_write_page_desc, map, &map);
+	expect_value(__wrap_write_page_desc, page_desc, &page_desc);
+	will_return(__wrap_write_page_desc, 0);
+
+	ret = write_upage(&map, NULL, &page_desc);
+
+	assert_int_equal(ret, 0);
+}
+
+static void test_page0(void **state)
+{
+	struct ftl_map map;
+	char page[4 * KIB], ret_page[4 * KIB];
+	struct ftl_page_desc page_desc;
+	int ret;
+
+	(void)state;
+
+	memset(page, 0x5a, sizeof page);
+	memset(ret_page, 0, sizeof ret_page);
+
+	map.log2_page_size = ilog2(4 * KIB);
+	map.head = 0;
+
+	will_return(__wrap_prepare_head, 0);
+
+	expect_value(__wrap_flash_write, addr, 0);
+	expect_value(__wrap_flash_write, len, 4 * KIB);
+	will_return(__wrap_flash_write, 4 * KIB);
+	will_return(__wrap_flash_write, &ret_page);
+
+	expect_value(__wrap_write_page_desc, map, &map);
+	expect_value(__wrap_write_page_desc, page_desc, &page_desc);
+	will_return(__wrap_write_page_desc, 0);
+
+	ret = write_upage(&map, &page, &page_desc);
+
+	assert_int_equal(ret, 0);
+	assert_memory_equal(page, ret_page, sizeof page);
+}
+
+static void test_page42(void **state)
+{
+	struct ftl_map map;
+	char page[4 * KIB], ret_page[4 * KIB];
+	struct ftl_page_desc page_desc;
+	int ret;
+
+	(void)state;
+
+	memset(page, 0x5a, sizeof page);
+	memset(ret_page, 0, sizeof ret_page);
+
+	map.log2_page_size = ilog2(4 * KIB);
+	map.head = 42;
+
+	will_return(__wrap_prepare_head, 0);
+
+	expect_value(__wrap_flash_write, addr, 42 * 4 * KIB);
+	expect_value(__wrap_flash_write, len, 4 * KIB);
+	will_return(__wrap_flash_write, 4 * KIB);
+	will_return(__wrap_flash_write, &ret_page);
+
+	expect_value(__wrap_write_page_desc, map, &map);
+	expect_value(__wrap_write_page_desc, page_desc, &page_desc);
+	will_return(__wrap_write_page_desc, 0);
+
+	ret = write_upage(&map, &page, &page_desc);
+
+	assert_int_equal(ret, 0);
+	assert_memory_equal(page, ret_page, sizeof page);
+}
+
+int test_write_upage(void)
+{
+	const struct CMUnitTest tests[] = {
+		{ "write_upage: prepare_head() = -1", test_prepare_head, NULL, NULL, NULL },
+		{ "write_upage: null page", test_null_page, NULL, NULL, NULL },
+		{ "write_upage: head=0", test_page0, NULL, NULL, NULL },
+		{ "write_upage: head=42", test_page42, NULL, NULL, NULL },
+	};
+
+	return cmocka_run_group_tests_name("write_upage", tests, NULL, NULL);
+}
diff --git a/source/tests/main.c b/source/tests/main.c
index 54975f2..e33ed35 100644
--- a/source/tests/main.c
+++ b/source/tests/main.c
@@ -70,6 +70,7 @@ int test_next_upage(void);
 int test_read_page_group(void);
 int test_read_page_desc(void);
 int test_write_page_desc(void);
+int test_write_upage(void);
 
 int main(void)
 {
@@ -80,6 +81,7 @@ int main(void)
 	count += test_read_page_group();
 	count += test_read_page_desc();
 	count += test_write_page_desc();
+	count += test_write_upage();
 
 	return count;
 }