diff --git a/cmds/incidentd/tests/FdBuffer_test.cpp b/cmds/incidentd/tests/FdBuffer_test.cpp
index 7a05d7e..9d208df 100644
--- a/cmds/incidentd/tests/FdBuffer_test.cpp
+++ b/cmds/incidentd/tests/FdBuffer_test.cpp
@@ -24,15 +24,16 @@
 #include <signal.h>
 #include <string.h>
 
+using namespace android;
+using namespace android::base;
+using namespace android::os::incidentd;
+using ::testing::Test;
+
 const int READ_TIMEOUT = 5 * 1000;
 const int BUFFER_SIZE = 16 * 1024;
 const int QUICK_TIMEOUT_MS = 100;
 const std::string HEAD = "[OK]";
 
-using namespace android;
-using namespace android::base;
-using ::testing::Test;
-
 class FdBufferTest : public Test {
 public:
     virtual void SetUp() override {
diff --git a/cmds/incidentd/tests/PrivacyBuffer_test.cpp b/cmds/incidentd/tests/PrivacyBuffer_test.cpp
index 10c2981..685759f 100644
--- a/cmds/incidentd/tests/PrivacyBuffer_test.cpp
+++ b/cmds/incidentd/tests/PrivacyBuffer_test.cpp
@@ -27,7 +27,7 @@
 using namespace android;
 using namespace android::base;
 using namespace android::os;
-using namespace std;
+using namespace android::os::incidentd;
 using ::testing::StrEq;
 using ::testing::Test;
 using ::testing::internal::CaptureStdout;
@@ -36,12 +36,12 @@
 const uint8_t OTHER_TYPE = 1;
 const uint8_t STRING_TYPE = 9;
 const uint8_t MESSAGE_TYPE = 11;
-const string STRING_FIELD_0 = "\x02\viamtestdata";
-const string VARINT_FIELD_1 = "\x08\x96\x01";  // 150
-const string STRING_FIELD_2 = "\x12\vandroidwins";
-const string FIX64_FIELD_3 = "\x19\xff\xff\xff\xff\xff\xff\xff\xff";  // -1
-const string FIX32_FIELD_4 = "\x25\xff\xff\xff\xff";                  // -1
-const string MESSAGE_FIELD_5 = "\x2a\x10" + VARINT_FIELD_1 + STRING_FIELD_2;
+const std::string STRING_FIELD_0 = "\x02\viamtestdata";
+const std::string VARINT_FIELD_1 = "\x08\x96\x01";  // 150
+const std::string STRING_FIELD_2 = "\x12\vandroidwins";
+const std::string FIX64_FIELD_3 = "\x19\xff\xff\xff\xff\xff\xff\xff\xff";  // -1
+const std::string FIX32_FIELD_4 = "\x25\xff\xff\xff\xff";                  // -1
+const std::string MESSAGE_FIELD_5 = "\x2a\x10" + VARINT_FIELD_1 + STRING_FIELD_2;
 
 class PrivacyBufferTest : public Test {
 public:
@@ -56,20 +56,20 @@
 
     virtual void SetUp() override { ASSERT_NE(tf.fd, -1); }
 
-    void writeToFdBuffer(string str) {
+    void writeToFdBuffer(std::string str) {
         ASSERT_TRUE(WriteStringToFile(str, tf.path));
         ASSERT_EQ(NO_ERROR, buffer.read(tf.fd, 10000));
         ASSERT_EQ(str.size(), buffer.size());
     }
 
-    void assertBuffer(PrivacyBuffer& buf, string expected) {
+    void assertBuffer(PrivacyBuffer& buf, std::string expected) {
         ASSERT_EQ(buf.size(), expected.size());
         CaptureStdout();
         ASSERT_EQ(buf.flush(STDOUT_FILENO), NO_ERROR);
         ASSERT_THAT(GetCapturedStdout(), StrEq(expected));
     }
 
-    void assertStrip(uint8_t dest, string expected, Privacy* policy) {
+    void assertStrip(uint8_t dest, std::string expected, Privacy* policy) {
         PrivacySpec spec = PrivacySpec::new_spec(dest);
         EncodedBuffer::iterator bufData = buffer.data();
         PrivacyBuffer privacyBuf(policy, bufData);
@@ -77,7 +77,7 @@
         assertBuffer(privacyBuf, expected);
     }
 
-    void assertStripByFields(uint8_t dest, string expected, int size, Privacy* privacy, ...) {
+    void assertStripByFields(uint8_t dest, std::string expected, int size, Privacy* privacy, ...) {
         Privacy* list[size + 1];
         list[0] = privacy;
         va_list args;
@@ -194,7 +194,7 @@
 TEST_F(PrivacyBufferTest, StripVarintAndString) {
     writeToFdBuffer(STRING_FIELD_0 + VARINT_FIELD_1 + STRING_FIELD_2 + FIX64_FIELD_3 +
                     FIX32_FIELD_4);
-    string expected = STRING_FIELD_0 + FIX64_FIELD_3 + FIX32_FIELD_4;
+    std::string expected = STRING_FIELD_0 + FIX64_FIELD_3 + FIX32_FIELD_4;
     assertStripByFields(DEST_EXPLICIT, expected, 2, create_privacy(1, OTHER_TYPE, DEST_LOCAL),
                         create_privacy(2, STRING_TYPE, DEST_LOCAL));
 }
@@ -202,7 +202,7 @@
 TEST_F(PrivacyBufferTest, StripVarintAndFixed64) {
     writeToFdBuffer(STRING_FIELD_0 + VARINT_FIELD_1 + STRING_FIELD_2 + FIX64_FIELD_3 +
                     FIX32_FIELD_4);
-    string expected = STRING_FIELD_0 + STRING_FIELD_2 + FIX32_FIELD_4;
+    std::string expected = STRING_FIELD_0 + STRING_FIELD_2 + FIX32_FIELD_4;
     assertStripByFields(DEST_EXPLICIT, expected, 2, create_privacy(1, OTHER_TYPE, DEST_LOCAL),
                         create_privacy(3, OTHER_TYPE, DEST_LOCAL));
 }
@@ -210,14 +210,14 @@
 TEST_F(PrivacyBufferTest, StripVarintInNestedMessage) {
     writeToFdBuffer(STRING_FIELD_0 + MESSAGE_FIELD_5);
     Privacy* list[] = {create_privacy(1, OTHER_TYPE, DEST_LOCAL), NULL};
-    string expected = STRING_FIELD_0 + "\x2a\xd" + STRING_FIELD_2;
+    std::string expected = STRING_FIELD_0 + "\x2a\xd" + STRING_FIELD_2;
     assertStripByFields(DEST_EXPLICIT, expected, 1, create_message_privacy(5, list));
 }
 
 TEST_F(PrivacyBufferTest, StripFix64AndVarintInNestedMessage) {
     writeToFdBuffer(STRING_FIELD_0 + FIX64_FIELD_3 + MESSAGE_FIELD_5);
     Privacy* list[] = {create_privacy(1, OTHER_TYPE, DEST_LOCAL), NULL};
-    string expected = STRING_FIELD_0 + "\x2a\xd" + STRING_FIELD_2;
+    std::string expected = STRING_FIELD_0 + "\x2a\xd" + STRING_FIELD_2;
     assertStripByFields(DEST_EXPLICIT, expected, 2, create_privacy(3, OTHER_TYPE, DEST_LOCAL),
                         create_message_privacy(5, list));
 }
@@ -262,7 +262,7 @@
     Privacy* field5 = create_message_privacy(5, NULL);
     Privacy* list[] = {create_privacy(1, OTHER_TYPE, DEST_LOCAL), field5, NULL};
     field5->children = list;
-    string expected = "\x2a\x1c" + STRING_FIELD_2 + "\x2a\xd" + STRING_FIELD_2;
+    std::string expected = "\x2a\x1c" + STRING_FIELD_2 + "\x2a\xd" + STRING_FIELD_2;
     assertStrip(DEST_EXPLICIT, expected, field5);
 }
 
@@ -271,6 +271,6 @@
     Privacy* list[] = {create_privacy(1, OTHER_TYPE, DEST_LOCAL), NULL};
     Privacy* autoMsg = create_privacy(5, MESSAGE_TYPE, DEST_AUTOMATIC);
     autoMsg->children = list;
-    string expected = "\x2a\xd" + STRING_FIELD_2;
+    std::string expected = "\x2a\xd" + STRING_FIELD_2;
     assertStripByFields(DEST_AUTOMATIC, expected, 1, autoMsg);
 }
diff --git a/cmds/incidentd/tests/Reporter_test.cpp b/cmds/incidentd/tests/Reporter_test.cpp
index 42d94f0..cf107c8 100644
--- a/cmds/incidentd/tests/Reporter_test.cpp
+++ b/cmds/incidentd/tests/Reporter_test.cpp
@@ -30,6 +30,7 @@
 using namespace android::base;
 using namespace android::binder;
 using namespace android::os;
+using namespace android::os::incidentd;
 using namespace std;
 using ::testing::StrEq;
 using ::testing::Test;
diff --git a/cmds/incidentd/tests/Section_test.cpp b/cmds/incidentd/tests/Section_test.cpp
index 2f6698b..9f92353 100644
--- a/cmds/incidentd/tests/Section_test.cpp
+++ b/cmds/incidentd/tests/Section_test.cpp
@@ -25,25 +25,26 @@
 #include <gtest/gtest.h>
 #include <string.h>
 
+using namespace android;
+using namespace android::base;
+using namespace android::binder;
+using namespace android::os;
+using namespace android::os::incidentd;
+using namespace android::util;
+using ::testing::StrEq;
+using ::testing::Test;
+using ::testing::internal::CaptureStdout;
+using ::testing::internal::GetCapturedStdout;
+
 const int TIMEOUT_PARSER = -1;
 const int NOOP_PARSER = 0;
 const int REVERSE_PARSER = 1;
 
 const int QUICK_TIMEOUT_MS = 100;
 
-const string VARINT_FIELD_1 = "\x08\x96\x01";  // 150
-const string STRING_FIELD_2 = "\x12\vandroidwins";
-const string FIX64_FIELD_3 = "\x19\xff\xff\xff\xff\xff\xff\xff\xff";  // -1
-
-using namespace android::base;
-using namespace android::binder;
-using namespace android::os;
-using namespace android::util;
-using namespace std;
-using ::testing::StrEq;
-using ::testing::Test;
-using ::testing::internal::CaptureStdout;
-using ::testing::internal::GetCapturedStdout;
+const std::string VARINT_FIELD_1 = "\x08\x96\x01";  // 150
+const std::string STRING_FIELD_2 = "\x12\vandroidwins";
+const std::string FIX64_FIELD_3 = "\x19\xff\xff\xff\xff\xff\xff\xff\xff";  // -1
 
 // NOTICE: this test requires /system/bin/incident_helper is installed.
 class SectionTest : public Test {
@@ -101,7 +102,7 @@
     requests.add(new ReportRequest(args2, new SimpleListener(), tf.fd));
     requests.setMainFd(STDOUT_FILENO);
 
-    string content;
+    std::string content;
     CaptureStdout();
     ASSERT_EQ(NO_ERROR, hs.Execute(&requests));
     EXPECT_THAT(GetCapturedStdout(), StrEq("\n\x5"
@@ -163,9 +164,9 @@
     size_t fileLen = testFile.size();
     size_t totalLen = 1 + get_varint_size(fileLen) + fileLen + 3 + gzFile.size();
     uint8_t header[20];
-    header[0] = '\x2'; // header 0 << 3 + 2
+    header[0] = '\x2';  // header 0 << 3 + 2
     uint8_t* ptr = write_raw_varint(header + 1, totalLen);
-    *ptr = '\n'; // header 1 << 3 + 2
+    *ptr = '\n';  // header 1 << 3 + 2
     ptr = write_raw_varint(++ptr, fileLen);
     expected.assign((const char*)header, ptr - header);
     expected += testFile + "\x12\x9F\x6" + gzFile;
@@ -227,7 +228,7 @@
     requests.setMainFd(STDOUT_FILENO);
     CaptureStdout();
     ASSERT_EQ(NO_ERROR, ls.Execute(&requests));
-    string results = GetCapturedStdout();
+    std::string results = GetCapturedStdout();
     EXPECT_FALSE(results.empty());
 }
 
@@ -236,7 +237,7 @@
     requests.setMainFd(STDOUT_FILENO);
     CaptureStdout();
     ASSERT_EQ(NO_ERROR, ls.Execute(&requests));
-    string results = GetCapturedStdout();
+    std::string results = GetCapturedStdout();
     EXPECT_FALSE(results.empty());
 }
 
@@ -304,7 +305,7 @@
     ASSERT_EQ(NO_ERROR, fs.Execute(&requests));
     EXPECT_THAT(GetCapturedStdout(), StrEq("\x02\r" + STRING_FIELD_2));
 
-    string content, expect;
+    std::string content, expect;
     expect = VARINT_FIELD_1 + STRING_FIELD_2 + FIX64_FIELD_3;
     char c = (char)expect.size();
     EXPECT_TRUE(ReadFileToString(output1.path, &content));
@@ -346,7 +347,7 @@
     ASSERT_EQ(NO_ERROR, fs.Execute(&requests));
     EXPECT_THAT(GetCapturedStdout(), StrEq("\x02\r" + STRING_FIELD_2));
 
-    string content, expect;
+    std::string content, expect;
     expect = STRING_FIELD_2 + FIX64_FIELD_3;
     char c = (char)expect.size();
 
diff --git a/cmds/incidentd/tests/Throttler_test.cpp b/cmds/incidentd/tests/Throttler_test.cpp
index 213dcef..8488c99 100644
--- a/cmds/incidentd/tests/Throttler_test.cpp
+++ b/cmds/incidentd/tests/Throttler_test.cpp
@@ -20,6 +20,8 @@
 #include <gmock/gmock.h>
 #include <gtest/gtest.h>
 
+using namespace android::os::incidentd;
+
 TEST(ThrottlerTest, DataSizeExceeded) {
     Throttler t(100, 100000);
     EXPECT_FALSE(t.shouldThrottle());
diff --git a/cmds/incidentd/tests/section_list.cpp b/cmds/incidentd/tests/section_list.cpp
index bd2d15c..1d7f2b6 100644
--- a/cmds/incidentd/tests/section_list.cpp
+++ b/cmds/incidentd/tests/section_list.cpp
@@ -1,6 +1,10 @@
 // This file is a dummy section_list.cpp used for test only.
 #include "section_list.h"
 
+namespace android {
+namespace os {
+namespace incidentd {
+
 const Section* SECTION_LIST[] = {NULL};
 
 Privacy sub_field_1{1, 1, NULL, DEST_LOCAL, NULL};
@@ -16,3 +20,7 @@
 const Privacy** PRIVACY_POLICY_LIST = const_cast<const Privacy**>(final_list);
 
 const int PRIVACY_POLICY_COUNT = 2;
+
+}  // namespace incidentd
+}  // namespace os
+}  // namespace android
\ No newline at end of file