diff --git a/.clang-tidy b/.clang-tidy
index e3c8194..15ad58f 100644
--- a/.clang-tidy
+++ b/.clang-tidy
@@ -219,6 +219,7 @@
 performance-for-range-copy,
 performance-implicit-conversion-in-loop,
 performance-inefficient-algorithm,
+performance-inefficient-string-concatenation,
 performance-inefficient-vector-operation,
 performance-move-const-arg,
 performance-move-constructor-init,
diff --git a/test/utest.cpp b/test/utest.cpp
index 778c845..9e55f2a 100644
--- a/test/utest.cpp
+++ b/test/utest.cpp
@@ -408,10 +408,15 @@
 TEST_F(FileTest, TestMergeFiles)
 {
     std::string retFile = tmpDir + "/retFile";
+    std::stringstream ss;
+    ss << "cat";
     for (const auto& file : srcFiles)
     {
-        command("cat " + file + " >> " + retFile);
+        ss << " " << file;
     }
+    ss << " >> " << retFile;
+    std::string catCommand = ss.str();
+    command(catCommand);
 
     std::string dstFile = tmpDir + "/dstFile";
     utils::mergeFiles(srcFiles, dstFile);