diff --git a/tests/component/install_test.cpp b/tests/component/install_test.cpp
index 27a01cb..47a5471 100644
--- a/tests/component/install_test.cpp
+++ b/tests/component/install_test.cpp
@@ -439,8 +439,8 @@
 
   std::vector<std::string> serial_numbers;
   // Creates a dummy serial number string.
-  for (size_t c = 'a'; c <= 'z'; c++) {
-    serial_numbers.emplace_back(c, serialno.size());
+  for (char c = 'a'; c <= 'z'; c++) {
+    serial_numbers.emplace_back(serialno.size(), c);
   }
 
   // No matched serialno found.