diff --git a/os/mingw.c b/os/mingw.c
index 7317dfb2..f4215c1d 100644
--- a/os/mingw.c
+++ b/os/mingw.c
@@ -2774,6 +2774,23 @@ int os_term(pid_t pid)
 	return 0;
 }
 
+int os_kill(pid_t pid)
+{
+	if (pid <= 0) {
+		errno = EINVAL;
+		return -1;
+	}
+
+	HANDLE h = (void*)pid;
+
+	if (!TerminateProcess(h, 1)) {
+		windows_errno(GetLastError());
+		return -1;
+	}
+
+	return 0;
+}
+
 int os_command(const char* command, const char* run_as_user, const char* stdin_text)
 {
 	wchar_t conv[CONV_MAX];
diff --git a/os/os.h b/os/os.h
index 16e4bbd1..a1f822b9 100644
--- a/os/os.h
+++ b/os/os.h
@@ -140,6 +140,13 @@ pid_t os_wait(pid_t pid, int* status);
  */
 int os_term(pid_t pid);
 
+/**
+ * Forcibly terminate a process.
+ * \param pid Process ID of the process to kill.
+ * \return 0 on success, -1 on failure.
+ */
+int os_kill(pid_t pid);
+
 /**
  * Fork and execute a verified executable, discarding all I/O.
  *
diff --git a/os/unix.c b/os/unix.c
index ed5a74d3..32466ae7 100644
--- a/os/unix.c
+++ b/os/unix.c
@@ -1300,6 +1300,11 @@ int os_wait(pid_t pid, int* status)
 
 int os_term(pid_t pid)
 {
+	if (pid <= 0) {
+		errno = EINVAL;
+		return -1;
+	}
+
 	/*
 	 * Send signal to the negative PID to target the entire Process Group.
 	 * This ensures that SnapRAID and any programs it may have spawned are
@@ -1308,6 +1313,17 @@ int os_term(pid_t pid)
 	return kill(-pid, SIGTERM);
 }
 
+int os_kill(pid_t pid)
+{
+	if (pid <= 0) {
+		errno = EINVAL;
+		return -1;
+	}
+
+	/* Send SIGKILL signal to the negative PID to target the entire Process Group */
+	return kill(-pid, SIGKILL);
+}
+
 int os_spawn_and_wait(const char** argv)
 {
 	pid_t pid = os_spawn((char**)argv, 0, 0, 0);