diff --git a/.clang-tidy b/.clang-tidy
index 6d73fdb3994b..ffdc2d0dd973 100644
--- a/.clang-tidy
+++ b/.clang-tidy
@@ -19,6 +19,7 @@ WarningsAsErrors: 'abseil-duration-*,
                    bugprone-assert-side-effect,
                    bugprone-unused-raii,
                    bugprone-use-after-move,
+                   modernize-deprecated-headers,
                    modernize-make-shared,
                    modernize-make-unique,
                    modernize-return-braced-init-list,
diff --git a/source/common/network/io_socket_handle_impl.cc b/source/common/network/io_socket_handle_impl.cc
index f2442973bd11..cce957655380 100644
--- a/source/common/network/io_socket_handle_impl.cc
+++ b/source/common/network/io_socket_handle_impl.cc
@@ -1,7 +1,6 @@
 #include "common/network/io_socket_handle_impl.h"
 
-#include <errno.h>
-
+#include <cerrno>
 #include <iostream>
 
 #include "envoy/buffer/buffer.h"
diff --git a/source/common/router/config_utility.h b/source/common/router/config_utility.h
index adfb1e9d2818..4a753964059f 100644
--- a/source/common/router/config_utility.h
+++ b/source/common/router/config_utility.h
@@ -1,7 +1,6 @@
 #pragma once
 
-#include <inttypes.h>
-
+#include <cinttypes>
 #include <regex>
 #include <string>
 #include <vector>
diff --git a/source/common/router/header_parser.cc b/source/common/router/header_parser.cc
index 05022605347c..e5d71aa9ef1f 100644
--- a/source/common/router/header_parser.cc
+++ b/source/common/router/header_parser.cc
@@ -1,7 +1,6 @@
 #include "common/router/header_parser.h"
 
-#include <ctype.h>
-
+#include <cctype>
 #include <memory>
 #include <string>
 
diff --git a/source/common/signal/signal_action.h b/source/common/signal/signal_action.h
index 12fcb1805a7b..b7ae17cd426b 100644
--- a/source/common/signal/signal_action.h
+++ b/source/common/signal/signal_action.h
@@ -1,9 +1,9 @@
 #pragma once
 
-#include <signal.h>
 #include <unistd.h>
 
 #include <algorithm>
+#include <csignal>
 #include <list>
 
 #include "common/common/non_copyable.h"
diff --git a/source/common/stats/isolated_store_impl.cc b/source/common/stats/isolated_store_impl.cc
index 83a99379c587..6f2da0f899af 100644
--- a/source/common/stats/isolated_store_impl.cc
+++ b/source/common/stats/isolated_store_impl.cc
@@ -1,8 +1,7 @@
 #include "common/stats/isolated_store_impl.h"
 
-#include <string.h>
-
 #include <algorithm>
+#include <cstring>
 #include <string>
 
 #include "common/common/utility.h"
diff --git a/source/common/stats/isolated_store_impl.h b/source/common/stats/isolated_store_impl.h
index ae22d13dfdba..ce6ddaca703b 100644
--- a/source/common/stats/isolated_store_impl.h
+++ b/source/common/stats/isolated_store_impl.h
@@ -1,8 +1,7 @@
 #pragma once
 
-#include <string.h>
-
 #include <algorithm>
+#include <cstring>
 #include <string>
 
 #include "envoy/stats/stats.h"
diff --git a/source/common/stats/tag_extractor_impl.cc b/source/common/stats/tag_extractor_impl.cc
index acf440fa695e..7bb02e6f53e1 100644
--- a/source/common/stats/tag_extractor_impl.cc
+++ b/source/common/stats/tag_extractor_impl.cc
@@ -1,7 +1,6 @@
 #include "common/stats/tag_extractor_impl.h"
 
-#include <string.h>
-
+#include <cstring>
 #include <string>
 
 #include "envoy/common/exception.h"
diff --git a/source/extensions/filters/listener/proxy_protocol/proxy_protocol.cc b/source/extensions/filters/listener/proxy_protocol/proxy_protocol.cc
index 9c6fb7b93997..f4dce6138b9c 100644
--- a/source/extensions/filters/listener/proxy_protocol/proxy_protocol.cc
+++ b/source/extensions/filters/listener/proxy_protocol/proxy_protocol.cc
@@ -1,11 +1,11 @@
 #include "extensions/filters/listener/proxy_protocol/proxy_protocol.h"
 
-#include <string.h>
 #include <sys/ioctl.h>
 #include <unistd.h>
 
 #include <algorithm>
 #include <cstdint>
+#include <cstring>
 #include <memory>
 #include <string>
 
diff --git a/source/extensions/filters/network/dubbo_proxy/conn_manager.cc b/source/extensions/filters/network/dubbo_proxy/conn_manager.cc
index 534b3d292964..b9a5f27d278f 100644
--- a/source/extensions/filters/network/dubbo_proxy/conn_manager.cc
+++ b/source/extensions/filters/network/dubbo_proxy/conn_manager.cc
@@ -1,6 +1,6 @@
 #include "extensions/filters/network/dubbo_proxy/conn_manager.h"
 
-#include <stdint.h>
+#include <cstdint>
 
 #include "envoy/common/exception.h"
 
diff --git a/source/extensions/filters/network/thrift_proxy/metadata.h b/source/extensions/filters/network/thrift_proxy/metadata.h
index 5c1469e86e3f..731514756656 100644
--- a/source/extensions/filters/network/thrift_proxy/metadata.h
+++ b/source/extensions/filters/network/thrift_proxy/metadata.h
@@ -1,8 +1,7 @@
 #pragma once
 
-#include <string.h>
-
 #include <algorithm>
+#include <cstring>
 #include <list>
 #include <memory>
 #include <string>
diff --git a/source/server/server.cc b/source/server/server.cc
index 117cd8a6b60f..107e99beeb1f 100644
--- a/source/server/server.cc
+++ b/source/server/server.cc
@@ -1,8 +1,7 @@
 #include "server/server.h"
 
-#include <signal.h>
-
 #include <atomic>
+#include <csignal>
 #include <cstdint>
 #include <functional>
 #include <memory>
diff --git a/test/common/signal/signals_test.cc b/test/common/signal/signals_test.cc
index 72b28c7bbf8b..0dda4fe752c8 100644
--- a/test/common/signal/signals_test.cc
+++ b/test/common/signal/signals_test.cc
@@ -1,6 +1,7 @@
-#include <signal.h>
 #include <sys/mman.h>
 
+#include <csignal>
+
 #include "common/signal/signal_action.h"
 
 #include "test/test_common/utility.h"
diff --git a/test/integration/tcp_dump.cc b/test/integration/tcp_dump.cc
index 1c3b76f124b7..95cd8b55c0e0 100644
--- a/test/integration/tcp_dump.cc
+++ b/test/integration/tcp_dump.cc
@@ -1,10 +1,10 @@
 #include "test/integration/tcp_dump.h"
 
-#include <signal.h>
 #include <sys/types.h>
 #include <sys/wait.h>
 #include <unistd.h>
 
+#include <csignal>
 #include <fstream>
 
 #include "common/common/assert.h"