diff --git a/redfish-core/lib/ut/service_root_test.cpp b/redfish-core/lib/ut/service_root_test.cpp
index 80918d2..06a7c21 100644
--- a/redfish-core/lib/ut/service_root_test.cpp
+++ b/redfish-core/lib/ut/service_root_test.cpp
@@ -11,7 +11,12 @@
 #include "gmock/gmock.h"
 #include "gtest/gtest.h"
 
-static void assertServiceRootGet(crow::Response& res)
+namespace redfish
+{
+namespace
+{
+
+void assertServiceRootGet(crow::Response& res)
 {
     nlohmann::json& json = res.jsonValue;
     EXPECT_EQ(json["@odata.id"], "/redfish/v1");
@@ -105,5 +110,8 @@
 
     shareAsyncResp->res.setCompleteRequestHandler(assertServiceRootGet);
 
-    redfish::handleServiceRootGet(shareAsyncResp);
+    handleServiceRootGet(shareAsyncResp);
 }
+
+} // namespace
+} // namespace redfish
\ No newline at end of file
diff --git a/redfish-core/ut/hex_utils_test.cpp b/redfish-core/ut/hex_utils_test.cpp
index 21387c6..05bcb9e 100644
--- a/redfish-core/ut/hex_utils_test.cpp
+++ b/redfish-core/ut/hex_utils_test.cpp
@@ -2,6 +2,9 @@
 
 #include <gmock/gmock.h>
 
+namespace
+{
+
 TEST(ToHexString, uint64)
 {
     EXPECT_EQ(intToHexString(0xFFFFFFFFFFFFFFFFULL, 16), "FFFFFFFFFFFFFFFF");
@@ -65,3 +68,5 @@
     EXPECT_TRUE(hexStringToBytes("`").empty());
     EXPECT_TRUE(hexStringToBytes("012").empty());
 }
+
+} // namespace
\ No newline at end of file
diff --git a/redfish-core/ut/ip_utils_test.cpp b/redfish-core/ut/ip_utils_test.cpp
index 455433b..c27ec99 100644
--- a/redfish-core/ut/ip_utils_test.cpp
+++ b/redfish-core/ut/ip_utils_test.cpp
@@ -2,8 +2,12 @@
 
 #include "gtest/gtest.h"
 
-using boost::asio::ip::make_address;
-using redfish::ip_util::toString;
+namespace redfish::ip_util
+{
+namespace
+{
+
+using ::boost::asio::ip::make_address;
 
 TEST(IpToString, v4mapped)
 {
@@ -18,3 +22,5 @@
               "fd03:f9ab:25de:89ec:1234:5678:90ab:cdef");
     EXPECT_EQ(toString(make_address("::ffff:127.0.0.1")), "127.0.0.1");
 }
+} // namespace
+} // namespace redfish::ip_util
\ No newline at end of file
diff --git a/redfish-core/ut/json_utils_test.cpp b/redfish-core/ut/json_utils_test.cpp
index ed8a79a..cd5504c 100644
--- a/redfish-core/ut/json_utils_test.cpp
+++ b/redfish-core/ut/json_utils_test.cpp
@@ -5,9 +5,10 @@
 
 #include <gmock/gmock.h>
 
-using redfish::json_util::readJson;
-using redfish::json_util::readJsonAction;
-using redfish::json_util::readJsonPatch;
+namespace redfish::json_util
+{
+namespace
+{
 
 TEST(readJson, ValidElements)
 {
@@ -327,3 +328,6 @@
     EXPECT_EQ(res.result(), boost::beast::http::status::ok);
     EXPECT_TRUE(res.jsonValue.empty());
 }
+
+} // namespace
+} // namespace redfish::json_util
\ No newline at end of file
diff --git a/redfish-core/ut/lock_test.cpp b/redfish-core/ut/lock_test.cpp
index 7ee2b71..10c51d3 100644
--- a/redfish-core/ut/lock_test.cpp
+++ b/redfish-core/ut/lock_test.cpp
@@ -4,10 +4,11 @@
 
 #include "gmock/gmock.h"
 
-namespace crow
+namespace crow::ibm_mc_lock
 {
-namespace ibm_mc_lock
+namespace
 {
+
 using SType = std::string;
 using LockRequest = std::tuple<SType, SType, SType, uint64_t, SegmentFlags>;
 using LockRequests = std::vector<LockRequest>;
@@ -354,5 +355,5 @@
     ASSERT_EQ(1, result.size());
 }
 
-} // namespace ibm_mc_lock
-} // namespace crow
+} // namespace
+} // namespace crow::ibm_mc_lock
diff --git a/redfish-core/ut/privileges_test.cpp b/redfish-core/ut/privileges_test.cpp
index 1613fbb..3813b54 100644
--- a/redfish-core/ut/privileges_test.cpp
+++ b/redfish-core/ut/privileges_test.cpp
@@ -6,7 +6,10 @@
 
 #include "gmock/gmock.h"
 
-using namespace redfish;
+namespace redfish
+{
+namespace
+{
 
 TEST(PrivilegeTest, PrivilegeConstructor)
 {
@@ -121,3 +124,5 @@
                     expectedPrivileges[2], expectedPrivileges[3],
                     expectedPrivileges[4]));
 }
+} // namespace
+} // namespace redfish
\ No newline at end of file
diff --git a/redfish-core/ut/registries_test.cpp b/redfish-core/ut/registries_test.cpp
index b75883c..c324fee 100644
--- a/redfish-core/ut/registries_test.cpp
+++ b/redfish-core/ut/registries_test.cpp
@@ -2,9 +2,13 @@
 
 #include "gmock/gmock.h"
 
+namespace redfish::registries
+{
+namespace
+{
+
 TEST(RedfishRegistries, fillMessageArgs)
 {
-    using redfish::registries::fillMessageArgs;
     std::string toFill("%1");
     fillMessageArgs({{"foo"}}, toFill);
     EXPECT_EQ(toFill, "foo");
@@ -17,3 +21,5 @@
     fillMessageArgs({{"foo", "bar"}}, toFill);
     EXPECT_EQ(toFill, "foo, bar");
 }
+} // namespace
+} // namespace redfish::registries
\ No newline at end of file
diff --git a/redfish-core/ut/stl_utils_test.cpp b/redfish-core/ut/stl_utils_test.cpp
index a5115bd..02a9c15 100644
--- a/redfish-core/ut/stl_utils_test.cpp
+++ b/redfish-core/ut/stl_utils_test.cpp
@@ -1,16 +1,21 @@
 #include "utils/stl_utils.hpp"
 
-#include <gmock/gmock.h>
+#include <string>
 
+#include <gtest/gtest.h>
+
+namespace redfish::stl_utils
+{
+namespace
+{
 TEST(STLUtilesTest, RemoveDuplicates)
 {
     std::vector<std::string> strVec = {"s1", "s4", "s1", "s2", "", "s3", "s3"};
 
-    auto iter =
-        redfish::stl_utils::firstDuplicate(strVec.begin(), strVec.end());
+    auto iter = firstDuplicate(strVec.begin(), strVec.end());
     EXPECT_EQ(*iter, "s3");
 
-    redfish::stl_utils::removeDuplicate(strVec);
+    removeDuplicate(strVec);
 
     EXPECT_EQ(strVec.size(), 5);
     EXPECT_EQ(strVec[0], "s1");
@@ -19,3 +24,5 @@
     EXPECT_EQ(strVec[3], "");
     EXPECT_EQ(strVec[4], "s3");
 }
+} // namespace
+} // namespace redfish::stl_utils
diff --git a/redfish-core/ut/time_utils_test.cpp b/redfish-core/ut/time_utils_test.cpp
index 0a88e65..ee2e037 100644
--- a/redfish-core/ut/time_utils_test.cpp
+++ b/redfish-core/ut/time_utils_test.cpp
@@ -2,24 +2,29 @@
 
 #include <gmock/gmock.h>
 
+namespace redfish::time_utils
+{
+namespace
+{
+
 TEST(FromDurationTest, PositiveTests)
 {
-    using redfish::time_utils::fromDurationString;
-    using std::chrono::milliseconds;
-    EXPECT_EQ(fromDurationString("PT12S"), milliseconds(12000));
-    EXPECT_EQ(fromDurationString("PT0.204S"), milliseconds(204));
-    EXPECT_EQ(fromDurationString("PT0.2S"), milliseconds(200));
-    EXPECT_EQ(fromDurationString("PT50M"), milliseconds(3000000));
-    EXPECT_EQ(fromDurationString("PT23H"), milliseconds(82800000));
-    EXPECT_EQ(fromDurationString("P51D"), milliseconds(4406400000));
-    EXPECT_EQ(fromDurationString("PT2H40M10.1S"), milliseconds(9610100));
-    EXPECT_EQ(fromDurationString("P20DT2H40M10.1S"), milliseconds(1737610100));
-    EXPECT_EQ(fromDurationString(""), milliseconds(0));
+    EXPECT_EQ(fromDurationString("PT12S"), std::chrono::milliseconds(12000));
+    EXPECT_EQ(fromDurationString("PT0.204S"), std::chrono::milliseconds(204));
+    EXPECT_EQ(fromDurationString("PT0.2S"), std::chrono::milliseconds(200));
+    EXPECT_EQ(fromDurationString("PT50M"), std::chrono::milliseconds(3000000));
+    EXPECT_EQ(fromDurationString("PT23H"), std::chrono::milliseconds(82800000));
+    EXPECT_EQ(fromDurationString("P51D"),
+              std::chrono::milliseconds(4406400000));
+    EXPECT_EQ(fromDurationString("PT2H40M10.1S"),
+              std::chrono::milliseconds(9610100));
+    EXPECT_EQ(fromDurationString("P20DT2H40M10.1S"),
+              std::chrono::milliseconds(1737610100));
+    EXPECT_EQ(fromDurationString(""), std::chrono::milliseconds(0));
 }
 
 TEST(FromDurationTest, NegativeTests)
 {
-    using redfish::time_utils::fromDurationString;
     EXPECT_EQ(fromDurationString("PTS"), std::nullopt);
     EXPECT_EQ(fromDurationString("P1T"), std::nullopt);
     EXPECT_EQ(fromDurationString("PT100M1000S100"), std::nullopt);
@@ -32,28 +37,25 @@
 }
 TEST(ToDurationTest, PositiveTests)
 {
-    using redfish::time_utils::toDurationString;
-    using std::chrono::milliseconds;
-    EXPECT_EQ(toDurationString(milliseconds(12000)), "PT12.000S");
-    EXPECT_EQ(toDurationString(milliseconds(204)), "PT0.204S");
-    EXPECT_EQ(toDurationString(milliseconds(200)), "PT0.200S");
-    EXPECT_EQ(toDurationString(milliseconds(3000000)), "PT50M");
-    EXPECT_EQ(toDurationString(milliseconds(82800000)), "PT23H");
-    EXPECT_EQ(toDurationString(milliseconds(4406400000)), "P51DT");
-    EXPECT_EQ(toDurationString(milliseconds(9610100)), "PT2H40M10.100S");
-    EXPECT_EQ(toDurationString(milliseconds(1737610100)), "P20DT2H40M10.100S");
+    EXPECT_EQ(toDurationString(std::chrono::milliseconds(12000)), "PT12.000S");
+    EXPECT_EQ(toDurationString(std::chrono::milliseconds(204)), "PT0.204S");
+    EXPECT_EQ(toDurationString(std::chrono::milliseconds(200)), "PT0.200S");
+    EXPECT_EQ(toDurationString(std::chrono::milliseconds(3000000)), "PT50M");
+    EXPECT_EQ(toDurationString(std::chrono::milliseconds(82800000)), "PT23H");
+    EXPECT_EQ(toDurationString(std::chrono::milliseconds(4406400000)), "P51DT");
+    EXPECT_EQ(toDurationString(std::chrono::milliseconds(9610100)),
+              "PT2H40M10.100S");
+    EXPECT_EQ(toDurationString(std::chrono::milliseconds(1737610100)),
+              "P20DT2H40M10.100S");
 }
 
 TEST(ToDurationTest, NegativeTests)
 {
-    using redfish::time_utils::toDurationString;
-    using std::chrono::milliseconds;
-    EXPECT_EQ(toDurationString(milliseconds(-250)), "");
+    EXPECT_EQ(toDurationString(std::chrono::milliseconds(-250)), "");
 }
 
 TEST(ToDurationStringFromUintTest, PositiveTests)
 {
-    using redfish::time_utils::toDurationStringFromUint;
     uint64_t maxAcceptedTimeMs =
         static_cast<uint64_t>(std::chrono::milliseconds::max().count());
 
@@ -66,7 +68,6 @@
 
 TEST(ToDurationStringFromUintTest, NegativeTests)
 {
-    using redfish::time_utils::toDurationStringFromUint;
     uint64_t minNotAcceptedTimeMs =
         static_cast<uint64_t>(std::chrono::milliseconds::max().count()) + 1;
 
@@ -74,3 +75,6 @@
     EXPECT_EQ(toDurationStringFromUint(static_cast<uint64_t>(-1)),
               std::nullopt);
 }
+
+} // namespace
+} // namespace redfish::time_utils