diff --git a/cpp/test/mocks.h b/cpp/test/mocks.h
index 919afd8d..103a911d 100644
--- a/cpp/test/mocks.h
+++ b/cpp/test/mocks.h
@@ -360,6 +360,7 @@ class MockSCSIHD : public SCSIHD //NOSONAR Ignore inheritance hierarchy depth in
 	FRIEND_TEST(ScsiHdTest, FinalizeSetup);
 	FRIEND_TEST(ScsiHdTest, GetProductData);
 	FRIEND_TEST(ScsiHdTest, SetUpModePages);
+	FRIEND_TEST(ScsiHdTest, DECUniquePage);
 	FRIEND_TEST(ScsiHdTest, GetSectorSizes);
 	FRIEND_TEST(ScsiHdTest, ModeSelect);
 	FRIEND_TEST(PiscsiExecutorTest, SetSectorSize);
diff --git a/cpp/test/scsihd_nec_test.cpp b/cpp/test/scsihd_nec_test.cpp
index 6b5cbd7c..bbcfed39 100644
--- a/cpp/test/scsihd_nec_test.cpp
+++ b/cpp/test/scsihd_nec_test.cpp
@@ -18,11 +18,12 @@ using namespace filesystem;
 
 void ScsiHdNecTest_SetUpModePages(map<int, vector<byte>>& pages)
 {
-	EXPECT_EQ(5, pages.size()) << "Unexpected number of mode pages";
+	EXPECT_EQ(6, pages.size()) << "Unexpected number of mode pages";
 	EXPECT_EQ(12, pages[1].size());
 	EXPECT_EQ(24, pages[3].size());
 	EXPECT_EQ(20, pages[4].size());
 	EXPECT_EQ(12, pages[8].size());
+	EXPECT_EQ(25, pages[37].size());
 	EXPECT_EQ(30, pages[48].size());
 }
 
diff --git a/cpp/test/scsihd_test.cpp b/cpp/test/scsihd_test.cpp
index 693f450b..921b9f63 100644
--- a/cpp/test/scsihd_test.cpp
+++ b/cpp/test/scsihd_test.cpp
@@ -13,11 +13,12 @@
 
 void ScsiHdTest_SetUpModePages(map<int, vector<byte>>& pages)
 {
-	EXPECT_EQ(5, pages.size()) << "Unexpected number of mode pages";
+	EXPECT_EQ(6, pages.size()) << "Unexpected number of mode pages";
 	EXPECT_EQ(12, pages[1].size());
 	EXPECT_EQ(24, pages[3].size());
 	EXPECT_EQ(24, pages[4].size());
 	EXPECT_EQ(12, pages[8].size());
+	EXPECT_EQ(25, pages[37].size());
 	EXPECT_EQ(30, pages[48].size());
 }
 
@@ -101,6 +102,20 @@ TEST(ScsiHdTest, SetUpModePages)
 	ScsiHdTest_SetUpModePages(pages);
 }
 
+TEST(ScsiHdTest, DECUniquePage)
+{
+	map<int, vector<byte>> pages;
+	vector<byte> buf;
+	MockSCSIHD hd(0, false);
+
+	EXPECT_NO_THROW(hd.SetUpModePages(pages, 0x25, false)) << "MODE SENSE(6) DEC unique page is supported";
+	EXPECT_NE(pages.end(), pages.find(0x25));
+	buf = pages[0x25];
+	EXPECT_EQ(static_cast<byte> (0x25 | 0x80), buf[0]);
+	EXPECT_EQ(static_cast<byte> (0x17), buf[1]);
+	EXPECT_EQ(static_cast<byte> (0x01), buf[2]);
+}
+
 TEST(ScsiHdTest, ModeSelect)
 {
 	MockSCSIHD hd({ 512 });