diff --git a/userspace/errno.h b/userspace/errno.h
new file mode 100644
index 0000000..1c36227
--- /dev/null
+++ b/userspace/errno.h
@@ -0,0 +1,37 @@
+#pragma once
+extern int errno;
+
+#define EPERM 1    /* Operation not permitted */
+#define ENOENT 2   /* No such file or directory */
+#define ESRCH 3    /* No such process */
+#define EINTR 4    /* Interrupted system call */
+#define EIO 5      /* I/O error */
+#define ENXIO 6    /* No such device or address */
+#define E2BIG 7    /* Argument list too long */
+#define ENOEXEC 8  /* Exec format error */
+#define EBADF 9    /* Bad file number */
+#define ECHILD 10  /* No child processes */
+#define EAGAIN 11  /* Try again */
+#define ENOMEM 12  /* Out of memory */
+#define EACCES 13  /* Permission denied */
+#define EFAULT 14  /* Bad address */
+#define ENOTBLK 15 /* Block device required */
+#define EBUSY 16   /* Device or resource busy */
+#define EEXIST 17  /* File exists */
+#define EXDEV 18   /* Cross-device link */
+#define ENODEV 19  /* No such device */
+#define ENOTDIR 20 /* Not a directory */
+#define EISDIR 21  /* Is a directory */
+#define EINVAL 22  /* Invalid argument */
+#define ENFILE 23  /* File table overflow */
+#define EMFILE 24  /* Too many open files */
+#define ENOTTY 25  /* Not a typewriter */
+#define ETXTBSY 26 /* Text file busy */
+#define EFBIG 27   /* File too large */
+#define ENOSPC 28  /* No space left on device */
+#define ESPIPE 29  /* Illegal seek */
+#define EROFS 30   /* Read-only file system */
+#define EMLINK 31  /* Too many links */
+#define EPIPE 32   /* Broken pipe */
+#define EDOM 33    /* Math argument out of domain of func */
+#define ERANGE 34  /* Math result not representable */