diff --git a/.github/workflows/pull_request.yml b/.github/workflows/pull_request.yml
index 753d801f..d212a627 100644
--- a/.github/workflows/pull_request.yml
+++ b/.github/workflows/pull_request.yml
@@ -9,10 +9,10 @@ jobs:
     name: Test
     uses: swiftlang/github-workflows/.github/workflows/swift_package_test.yml@main
     with:
-      linux_os_versions: '["noble", "jammy", "focal", "rhel-ubi9", "bookworm"]'
+      linux_os_versions: '["amazonlinux2", "bookworm", "noble", "jammy", "focal", "rhel-ubi9"]'
       linux_swift_versions: '["6.1", "nightly-main"]'
       linux_pre_build_command: |
-        if command -v apt-get >/dev/null 2>&1 ; then # noble, jammy, focal, or bookworm
+        if command -v apt-get >/dev/null 2>&1 ; then # bookworm, noble, jammy, focal
           apt-get update -y
 
           # Test dependencies
@@ -22,6 +22,11 @@ jobs:
 
           # Test dependencies
           dnf install -y procps
+        elif command -v yum >/dev/null 2>&1 ; then # amazonlinux2
+          yum update -y
+
+          # Test dependencies
+          yum install -y procps
         fi
       windows_swift_versions: '["6.1", "nightly-main"]'
       enable_macos_checks: true
diff --git a/README.md b/README.md
index 233b7cbc..a1c78dc7 100644
--- a/README.md
+++ b/README.md
@@ -222,18 +222,20 @@ Use it by setting`.bytes(limit:)` for `output` or `error`.
 
 The table below describes the current level of support that Subprocess has for various platforms:
 
-| **Platform** | **Support Status** |
-|---|---|
-| **macOS** | Supported |
-| **iOS** | Not supported |
-| **watchOS** | Not supported |
-| **tvOS** | Not supported |
-| **visionOS** | Not supported |
-| **Ubuntu 22.04** | Supported |
-| **Ubuntu 24.04** | Supported |
-| **Red Hat Universal Base Image 9** | Supported |
-| **Debian 12** | Supported |
-| **Windows** | Supported |
+| **Platform**                       | **Support Status** |
+| ---------------------------------- | ------------------ |
+| **macOS**                          | Supported          |
+| **iOS**                            | Not supported      |
+| **watchOS**                        | Not supported      |
+| **tvOS**                           | Not supported      |
+| **visionOS**                       | Not supported      |
+| **Ubuntu 20.04**                   | Supported          |
+| **Ubuntu 22.04**                   | Supported          |
+| **Ubuntu 24.04**                   | Supported          |
+| **Red Hat Universal Base Image 9** | Supported          |
+| **Debian 12**                      | Supported          |
+| **Amazon Linux 2**                 | Supported          |
+| **Windows**                        | Supported          |
 
 <p align="right">(<a href="#readme-top">back to top</a>)</p>
 
diff --git a/Sources/_SubprocessCShims/process_shims.c b/Sources/_SubprocessCShims/process_shims.c
index 376abbd0..d456f4ca 100644
--- a/Sources/_SubprocessCShims/process_shims.c
+++ b/Sources/_SubprocessCShims/process_shims.c
@@ -73,6 +73,10 @@ int _was_process_suspended(int status) {
 #if TARGET_OS_LINUX
 #include <stdio.h>
 
+#ifndef SYS_pidfd_send_signal
+#define SYS_pidfd_send_signal 424
+#endif 
+
 int _shims_snprintf(
     char * _Nonnull str,
     int len,
@@ -322,6 +326,10 @@ int _subprocess_spawn(
 #define __GLIBC_PREREQ(maj, min) 0
 #endif
 
+#ifndef SYS_pidfd_open
+#define SYS_pidfd_open 434
+#endif
+
 int _pidfd_open(pid_t pid) {
     return syscall(SYS_pidfd_open, pid, 0);
 }
@@ -332,6 +340,10 @@ int _pidfd_open(pid_t pid) {
 #define SYS_clone3 435
 #endif
 
+#ifndef CLONE_PIDFD
+#define CLONE_PIDFD 0x00001000
+#endif
+
 // Can't use clone_args from sched.h because only Glibc defines it; Musl does not (and there's no macro to detect Musl)
 struct _subprocess_clone_args {
     uint64_t flags;