diff --git a/cpp/devices/scsihd.cpp b/cpp/devices/scsihd.cpp
index 9a8fb216..0b0cca89 100644
--- a/cpp/devices/scsihd.cpp
+++ b/cpp/devices/scsihd.cpp
@@ -36,9 +36,9 @@ string SCSIHD::GetProductData() const
 	uint64_t capacity = GetBlockCount() * GetSectorSizeInBytes();
 	string unit;
 
-	// 10 GiB and more
-	if (capacity >= 1'099'511'627'776) {
-		capacity /= 1'099'511'627'776;
+	// 10,000 MiB and more
+	if (capacity >= 10'485'760'000) {
+		capacity /= 1'073'741'824;
 		unit = "GiB";
 	}
 	// 1 MiB and more
diff --git a/cpp/test/scsihd_test.cpp b/cpp/test/scsihd_test.cpp
index b1ff985e..179c7170 100644
--- a/cpp/test/scsihd_test.cpp
+++ b/cpp/test/scsihd_test.cpp
@@ -69,10 +69,10 @@ TEST(ScsiHdTest, GetProductData)
 
 	hd_gb.SetFilename(string(filename));
 	hd_gb.SetSectorSizeInBytes(1024);
-	hd_gb.SetBlockCount(1'099'511'627'776 / 1024);
+	hd_gb.SetBlockCount(10'737'418'240 / 1024);
 	hd_gb.FinalizeSetup(0);
 	s = hd_gb.GetProduct();
-	EXPECT_NE(string::npos, s.find("1 GiB"));
+	EXPECT_NE(string::npos, s.find("10 GiB"));
 	remove(filename);
 }