diff --git a/libc/config/linux/aarch64/headers.txt b/libc/config/linux/aarch64/headers.txt
index 6d3bc9188583b..0573851fbc20b 100644
--- a/libc/config/linux/aarch64/headers.txt
+++ b/libc/config/linux/aarch64/headers.txt
@@ -18,6 +18,7 @@ set(TARGET_PUBLIC_HEADERS
     libc.include.locale
     libc.include.malloc
     libc.include.math
+    libc.include.netinet_in
     libc.include.poll
     libc.include.pthread
     libc.include.sched
diff --git a/libc/config/linux/riscv/headers.txt b/libc/config/linux/riscv/headers.txt
index 6d3bc9188583b..0573851fbc20b 100644
--- a/libc/config/linux/riscv/headers.txt
+++ b/libc/config/linux/riscv/headers.txt
@@ -18,6 +18,7 @@ set(TARGET_PUBLIC_HEADERS
     libc.include.locale
     libc.include.malloc
     libc.include.math
+    libc.include.netinet_in
     libc.include.poll
     libc.include.pthread
     libc.include.sched
diff --git a/libc/config/linux/x86_64/headers.txt b/libc/config/linux/x86_64/headers.txt
index 6d3bc9188583b..0573851fbc20b 100644
--- a/libc/config/linux/x86_64/headers.txt
+++ b/libc/config/linux/x86_64/headers.txt
@@ -18,6 +18,7 @@ set(TARGET_PUBLIC_HEADERS
     libc.include.locale
     libc.include.malloc
     libc.include.math
+    libc.include.netinet_in
     libc.include.poll
     libc.include.pthread
     libc.include.sched
diff --git a/libc/include/CMakeLists.txt b/libc/include/CMakeLists.txt
index 8fd37b0ee5ad6..afa90e6c8b655 100644
--- a/libc/include/CMakeLists.txt
+++ b/libc/include/CMakeLists.txt
@@ -191,6 +191,17 @@ add_header_macro(
     .inttypes
 )
 
+file(MAKE_DIRECTORY ${LIBC_INCLUDE_DIR}/netinet)
+
+add_header_macro(
+  netinet_in
+  ../libc/include/netinet/in.yaml
+  netinet/in.h
+  DEPENDS
+    .llvm_libc_common_h
+    .llvm-libc-macros.netinet_in_macros
+)
+
 add_header_macro(
   assert
   ../libc/include/assert.yaml
diff --git a/libc/include/llvm-libc-macros/CMakeLists.txt b/libc/include/llvm-libc-macros/CMakeLists.txt
index f71540313f0b3..76c03d913ee12 100644
--- a/libc/include/llvm-libc-macros/CMakeLists.txt
+++ b/libc/include/llvm-libc-macros/CMakeLists.txt
@@ -152,6 +152,12 @@ add_macro_header(
     .math_macros
 )
 
+add_macro_header(
+  netinet_in_macros
+  HDR
+    netinet-in-macros.h
+)
+
 add_macro_header(
   offsetof_macro
   HDR
diff --git a/libc/include/llvm-libc-macros/netinet-in-macros.h b/libc/include/llvm-libc-macros/netinet-in-macros.h
new file mode 100644
index 0000000000000..c05e5e2aec248
--- /dev/null
+++ b/libc/include/llvm-libc-macros/netinet-in-macros.h
@@ -0,0 +1,19 @@
+//===-- Definition of macros from netinet/in.h ----------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_MACROS_NETINET_IN_MACROS_H
+#define LLVM_LIBC_MACROS_NETINET_IN_MACROS_H
+
+#define IPPROTO_IP 0
+#define IPPROTO_ICMP 1
+#define IPPROTO_TCP 6
+#define IPPROTO_UDP 17
+#define IPPROTO_IPV6 41
+#define IPPROTO_RAW 255
+
+#endif // LLVM_LIBC_MACROS_NETINET_IN_MACROS_H
diff --git a/libc/include/netinet/in.h.def b/libc/include/netinet/in.h.def
new file mode 100644
index 0000000000000..d9a6a6ebe375d
--- /dev/null
+++ b/libc/include/netinet/in.h.def
@@ -0,0 +1,18 @@
+//===-- C standard library header in.h ------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_NETINET_IN_H
+#define LLVM_LIBC_NETINET_IN_H
+
+#include "__llvm-libc-common.h"
+
+#include "../llvm-libc-macros/netinet-in-macros.h"
+
+%%public_api()
+
+#endif // LLVM_LIBC_NETINET_IN_H
diff --git a/libc/include/netinet/in.yaml b/libc/include/netinet/in.yaml
new file mode 100644
index 0000000000000..fbd798d60cbf9
--- /dev/null
+++ b/libc/include/netinet/in.yaml
@@ -0,0 +1,7 @@
+header: netinet/in.h
+header_template: in.h.def
+macros: []
+types: []
+enums: []
+objects: []
+functions: []
diff --git a/libc/test/include/CMakeLists.txt b/libc/test/include/CMakeLists.txt
index 11e4c3a84157f..3ac5615d7e209 100644
--- a/libc/test/include/CMakeLists.txt
+++ b/libc/test/include/CMakeLists.txt
@@ -207,6 +207,16 @@ add_libc_test(
     libc.include.llvm-libc-macros.math_function_macros
 )
 
+add_libc_test(
+  netinet_in_test
+  SUITE
+    libc_include_tests
+  SRCS
+    netinet_in_test.cpp
+  DEPENDS
+    libc.include.llvm-libc-macros.netinet_in_macros
+)
+
 add_libc_test(
   signbit_test
   SUITE
diff --git a/libc/test/include/netinet_in_test.cpp b/libc/test/include/netinet_in_test.cpp
new file mode 100644
index 0000000000000..a6c47a779ea44
--- /dev/null
+++ b/libc/test/include/netinet_in_test.cpp
@@ -0,0 +1,19 @@
+//===-- Unittests for netinet/in macro ------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "include/llvm-libc-macros/netinet-in-macros.h"
+#include "test/UnitTest/Test.h"
+
+TEST(LlvmLibcNetinetInTest, IPPROTOMacro) {
+  EXPECT_EQ(IPPROTO_IP, 0);
+  EXPECT_EQ(IPPROTO_ICMP, 1);
+  EXPECT_EQ(IPPROTO_TCP, 6);
+  EXPECT_EQ(IPPROTO_UDP, 17);
+  EXPECT_EQ(IPPROTO_IPV6, 41);
+  EXPECT_EQ(IPPROTO_RAW, 255);
+}