diff --git a/expected/wasm32-wasi-eh/predefined-macros.txt b/expected/wasm32-wasi-eh/predefined-macros.txt
index 826a19ac0..efd1ede6d 100644
--- a/expected/wasm32-wasi-eh/predefined-macros.txt
+++ b/expected/wasm32-wasi-eh/predefined-macros.txt
@@ -2461,7 +2461,7 @@
 #define POLLIN POLLRDNORM
 #define POLLNVAL 0x4000
 #define POLLOUT POLLWRNORM
-#define POLLPRI POLLIN
+#define POLLPRI 0x4
 #define POLLRDNORM 0x1
 #define POLLWRNORM 0x2
 #define POSIX_CLOSE_RESTART 0
@@ -6082,6 +6082,7 @@
 #define __WASI_EVENTFDFLAGS_SEMAPHORE ((__wasi_eventfdflags_t)+(1 << 0))
 #define __WASI_EVENTRWFLAGS_FD_READWRITE_HANGUP ((__wasi_eventrwflags_t)+(1 << 0))
 #define __WASI_EVENTTYPE_CLOCK (UINT8_C(0))
+#define __WASI_EVENTTYPE_FD_EXCEPT (UINT8_C(3))
 #define __WASI_EVENTTYPE_FD_READ (UINT8_C(1))
 #define __WASI_EVENTTYPE_FD_WRITE (UINT8_C(2))
 #define __WASI_FDFLAGSEXT_CLOEXEC ((__wasi_fdflagsext_t)+(1 << 0))
@@ -6125,6 +6126,7 @@
 #define __WASI_PROC_SPAWN_FD_OP_NAME_OPEN (UINT8_C(2))
 #define __WASI_RIFLAGS_RECV_DATA_TRUNCATED ((__wasi_riflags_t)+(1 << 2))
 #define __WASI_RIFLAGS_RECV_DONT_WAIT ((__wasi_riflags_t)+(1 << 3))
+#define __WASI_RIFLAGS_RECV_OOB ((__wasi_riflags_t)+(1 << 4))
 #define __WASI_RIFLAGS_RECV_PEEK ((__wasi_riflags_t)+(1 << 0))
 #define __WASI_RIFLAGS_RECV_WAITALL ((__wasi_riflags_t)+(1 << 1))
 #define __WASI_RIGHTS_FD_ADVISE ((__wasi_rights_t)+(1 << 7))
@@ -6170,6 +6172,7 @@
 #define __WASI_SDFLAGS_RD ((__wasi_sdflags_t)+(1 << 0))
 #define __WASI_SDFLAGS_WR ((__wasi_sdflags_t)+(1 << 1))
 #define __WASI_SIFLAGS_SEND_DONT_WAIT ((__wasi_siflags_t)+(1 << 0))
+#define __WASI_SIFLAGS_SEND_OOB ((__wasi_siflags_t)+(1 << 1))
 #define __WASI_SIGNAL_ABRT (UINT8_C(6))
 #define __WASI_SIGNAL_ALRM (UINT8_C(14))
 #define __WASI_SIGNAL_BUS (UINT8_C(7))
diff --git a/expected/wasm32-wasi-ehpic/predefined-macros.txt b/expected/wasm32-wasi-ehpic/predefined-macros.txt
index 8081fbcf5..3eb41e26d 100644
--- a/expected/wasm32-wasi-ehpic/predefined-macros.txt
+++ b/expected/wasm32-wasi-ehpic/predefined-macros.txt
@@ -2461,7 +2461,7 @@
 #define POLLIN POLLRDNORM
 #define POLLNVAL 0x4000
 #define POLLOUT POLLWRNORM
-#define POLLPRI POLLIN
+#define POLLPRI 0x4
 #define POLLRDNORM 0x1
 #define POLLWRNORM 0x2
 #define POSIX_CLOSE_RESTART 0
@@ -6091,6 +6091,7 @@
 #define __WASI_EVENTFDFLAGS_SEMAPHORE ((__wasi_eventfdflags_t)+(1 << 0))
 #define __WASI_EVENTRWFLAGS_FD_READWRITE_HANGUP ((__wasi_eventrwflags_t)+(1 << 0))
 #define __WASI_EVENTTYPE_CLOCK (UINT8_C(0))
+#define __WASI_EVENTTYPE_FD_EXCEPT (UINT8_C(3))
 #define __WASI_EVENTTYPE_FD_READ (UINT8_C(1))
 #define __WASI_EVENTTYPE_FD_WRITE (UINT8_C(2))
 #define __WASI_FDFLAGSEXT_CLOEXEC ((__wasi_fdflagsext_t)+(1 << 0))
@@ -6134,6 +6135,7 @@
 #define __WASI_PROC_SPAWN_FD_OP_NAME_OPEN (UINT8_C(2))
 #define __WASI_RIFLAGS_RECV_DATA_TRUNCATED ((__wasi_riflags_t)+(1 << 2))
 #define __WASI_RIFLAGS_RECV_DONT_WAIT ((__wasi_riflags_t)+(1 << 3))
+#define __WASI_RIFLAGS_RECV_OOB ((__wasi_riflags_t)+(1 << 4))
 #define __WASI_RIFLAGS_RECV_PEEK ((__wasi_riflags_t)+(1 << 0))
 #define __WASI_RIFLAGS_RECV_WAITALL ((__wasi_riflags_t)+(1 << 1))
 #define __WASI_RIGHTS_FD_ADVISE ((__wasi_rights_t)+(1 << 7))
@@ -6179,6 +6181,7 @@
 #define __WASI_SDFLAGS_RD ((__wasi_sdflags_t)+(1 << 0))
 #define __WASI_SDFLAGS_WR ((__wasi_sdflags_t)+(1 << 1))
 #define __WASI_SIFLAGS_SEND_DONT_WAIT ((__wasi_siflags_t)+(1 << 0))
+#define __WASI_SIFLAGS_SEND_OOB ((__wasi_siflags_t)+(1 << 1))
 #define __WASI_SIGNAL_ABRT (UINT8_C(6))
 #define __WASI_SIGNAL_ALRM (UINT8_C(14))
 #define __WASI_SIGNAL_BUS (UINT8_C(7))
diff --git a/expected/wasm32-wasi-threads/predefined-macros.txt b/expected/wasm32-wasi-threads/predefined-macros.txt
index 2c80edec3..acdd763cf 100644
--- a/expected/wasm32-wasi-threads/predefined-macros.txt
+++ b/expected/wasm32-wasi-threads/predefined-macros.txt
@@ -2357,7 +2357,7 @@
 #define POLLIN POLLRDNORM
 #define POLLNVAL 0x4000
 #define POLLOUT POLLWRNORM
-#define POLLPRI POLLIN
+#define POLLPRI 0x4
 #define POLLRDNORM 0x1
 #define POLLWRNORM 0x2
 #define POSIX_CLOSE_RESTART 0
@@ -5881,6 +5881,7 @@
 #define __WASI_EVENTFDFLAGS_SEMAPHORE ((__wasi_eventfdflags_t)(1 << 0))
 #define __WASI_EVENTRWFLAGS_FD_READWRITE_HANGUP ((__wasi_eventrwflags_t)(1 << 0))
 #define __WASI_EVENTTYPE_CLOCK (UINT8_C(0))
+#define __WASI_EVENTTYPE_FD_EXCEPT (UINT8_C(3))
 #define __WASI_EVENTTYPE_FD_READ (UINT8_C(1))
 #define __WASI_EVENTTYPE_FD_WRITE (UINT8_C(2))
 #define __WASI_FDFLAGS_APPEND ((__wasi_fdflags_t)(1 << 0))
diff --git a/expected/wasm32-wasi/predefined-macros.txt b/expected/wasm32-wasi/predefined-macros.txt
index d75a22804..314ea294c 100644
--- a/expected/wasm32-wasi/predefined-macros.txt
+++ b/expected/wasm32-wasi/predefined-macros.txt
@@ -2461,7 +2461,7 @@
 #define POLLIN POLLRDNORM
 #define POLLNVAL 0x4000
 #define POLLOUT POLLWRNORM
-#define POLLPRI POLLIN
+#define POLLPRI 0x4
 #define POLLRDNORM 0x1
 #define POLLWRNORM 0x2
 #define POSIX_CLOSE_RESTART 0
@@ -6090,6 +6090,7 @@
 #define __WASI_EVENTFDFLAGS_SEMAPHORE ((__wasi_eventfdflags_t)+(1 << 0))
 #define __WASI_EVENTRWFLAGS_FD_READWRITE_HANGUP ((__wasi_eventrwflags_t)+(1 << 0))
 #define __WASI_EVENTTYPE_CLOCK (UINT8_C(0))
+#define __WASI_EVENTTYPE_FD_EXCEPT (UINT8_C(3))
 #define __WASI_EVENTTYPE_FD_READ (UINT8_C(1))
 #define __WASI_EVENTTYPE_FD_WRITE (UINT8_C(2))
 #define __WASI_FDFLAGSEXT_CLOEXEC ((__wasi_fdflagsext_t)+(1 << 0))
@@ -6133,6 +6134,7 @@
 #define __WASI_PROC_SPAWN_FD_OP_NAME_OPEN (UINT8_C(2))
 #define __WASI_RIFLAGS_RECV_DATA_TRUNCATED ((__wasi_riflags_t)+(1 << 2))
 #define __WASI_RIFLAGS_RECV_DONT_WAIT ((__wasi_riflags_t)+(1 << 3))
+#define __WASI_RIFLAGS_RECV_OOB ((__wasi_riflags_t)+(1 << 4))
 #define __WASI_RIFLAGS_RECV_PEEK ((__wasi_riflags_t)+(1 << 0))
 #define __WASI_RIFLAGS_RECV_WAITALL ((__wasi_riflags_t)+(1 << 1))
 #define __WASI_RIGHTS_FD_ADVISE ((__wasi_rights_t)+(1 << 7))
@@ -6178,6 +6180,7 @@
 #define __WASI_SDFLAGS_RD ((__wasi_sdflags_t)+(1 << 0))
 #define __WASI_SDFLAGS_WR ((__wasi_sdflags_t)+(1 << 1))
 #define __WASI_SIFLAGS_SEND_DONT_WAIT ((__wasi_siflags_t)+(1 << 0))
+#define __WASI_SIFLAGS_SEND_OOB ((__wasi_siflags_t)+(1 << 1))
 #define __WASI_SIGNAL_ABRT (UINT8_C(6))
 #define __WASI_SIGNAL_ALRM (UINT8_C(14))
 #define __WASI_SIGNAL_BUS (UINT8_C(7))
diff --git a/expected/wasm64-wasi/predefined-macros.txt b/expected/wasm64-wasi/predefined-macros.txt
index 77144a3e1..e10d68aa0 100644
--- a/expected/wasm64-wasi/predefined-macros.txt
+++ b/expected/wasm64-wasi/predefined-macros.txt
@@ -2403,7 +2403,7 @@
 #define POLLIN POLLRDNORM
 #define POLLNVAL 0x4000
 #define POLLOUT POLLWRNORM
-#define POLLPRI POLLIN
+#define POLLPRI 0x4
 #define POLLRDNORM 0x1
 #define POLLWRNORM 0x2
 #define POSIX_CLOSE_RESTART 0
@@ -5946,6 +5946,7 @@
 #define __WASI_EVENTFDFLAGS_SEMAPHORE ((__wasi_eventfdflags_t)(1 << 0))
 #define __WASI_EVENTRWFLAGS_FD_READWRITE_HANGUP ((__wasi_eventrwflags_t)(1 << 0))
 #define __WASI_EVENTTYPE_CLOCK (UINT8_C(0))
+#define __WASI_EVENTTYPE_FD_EXCEPT (UINT8_C(3))
 #define __WASI_EVENTTYPE_FD_READ (UINT8_C(1))
 #define __WASI_EVENTTYPE_FD_WRITE (UINT8_C(2))
 #define __WASI_FDFLAGS_APPEND ((__wasi_fdflags_t)(1 << 0))
diff --git a/libc-bottom-half/cloudlibc/src/libc/poll/poll.c b/libc-bottom-half/cloudlibc/src/libc/poll/poll.c
index 3ceb432ca..05c3cacac 100644
--- a/libc-bottom-half/cloudlibc/src/libc/poll/poll.c
+++ b/libc-bottom-half/cloudlibc/src/libc/poll/poll.c
@@ -9,7 +9,7 @@
 
 int poll(struct pollfd *fds, size_t nfds, int timeout) {
   // Construct events for poll().
-  size_t maxevents = 2 * nfds + 1;
+  size_t maxevents = 3 * nfds + 1;
   __wasi_subscription_t subscriptions[maxevents];
   size_t nsubscriptions = 0;
   for (size_t i = 0; i < nfds; ++i) {
@@ -35,6 +35,15 @@ int poll(struct pollfd *fds, size_t nfds, int timeout) {
       };
       created_events = true;
     }
+    if ((pollfd->events & POLLPRI) != 0) {
+      __wasi_subscription_t *subscription = &subscriptions[nsubscriptions++];
+      *subscription = (__wasi_subscription_t){
+          .userdata = (uintptr_t)pollfd,
+          .u.tag = __WASI_EVENTTYPE_FD_EXCEPT,
+          .u.u.fd_read.file_descriptor = pollfd->fd,
+      };
+      created_events = true;
+    }
 
     // As entries are decomposed into separate read/write subscriptions,
     // we cannot detect POLLERR, POLLHUP and POLLNVAL if POLLRDNORM and
@@ -91,7 +100,8 @@ int poll(struct pollfd *fds, size_t nfds, int timeout) {
   for (size_t i = 0; i < nevents; ++i) {
     const __wasi_event_t *event = &events[i];
     if (event->type == __WASI_EVENTTYPE_FD_READ ||
-        event->type == __WASI_EVENTTYPE_FD_WRITE) {
+        event->type == __WASI_EVENTTYPE_FD_WRITE ||
+        event->type == __WASI_EVENTTYPE_FD_EXCEPT) {
       struct pollfd *pollfd = (struct pollfd *)(uintptr_t)event->userdata;
       if (event->error == __WASI_ERRNO_BADF) {
         // Invalid file descriptor.
@@ -103,7 +113,7 @@ int poll(struct pollfd *fds, size_t nfds, int timeout) {
         // Another error occurred.
         pollfd->revents |= POLLERR;
       } else {
-        // Data can be read or written.
+        // Data can be read or written, or an exceptional condition is pending.
         if (event->type == __WASI_EVENTTYPE_FD_READ) {
             pollfd->revents |= POLLRDNORM;
             if (event->fd_readwrite.flags & __WASI_EVENTRWFLAGS_FD_READWRITE_HANGUP) {
@@ -114,6 +124,8 @@ int poll(struct pollfd *fds, size_t nfds, int timeout) {
             if (event->fd_readwrite.flags & __WASI_EVENTRWFLAGS_FD_READWRITE_HANGUP) {
               pollfd->revents |= POLLHUP;
             }
+        } else if (event->type == __WASI_EVENTTYPE_FD_EXCEPT) {
+            pollfd->revents |= POLLPRI;
         }
       }
     }
diff --git a/libc-bottom-half/cloudlibc/src/libc/sys/select/pselect.c b/libc-bottom-half/cloudlibc/src/libc/sys/select/pselect.c
index d555040e1..d1b722837 100644
--- a/libc-bottom-half/cloudlibc/src/libc/sys/select/pselect.c
+++ b/libc-bottom-half/cloudlibc/src/libc/sys/select/pselect.c
@@ -18,13 +18,6 @@ int pselect(int nfds, fd_set *restrict readfds, fd_set *restrict writefds,
     return -1;
   }
 
-  // This implementation does not support polling for exceptional
-  // conditions, such as out-of-band data on TCP sockets.
-  if (errorfds != NULL && errorfds->__nfds > 0) {
-    errno = ENOSYS;
-    return -1;
-  }
-
   // Replace NULL pointers by the empty set.
   fd_set empty;
   FD_ZERO(&empty);
@@ -32,9 +25,11 @@ int pselect(int nfds, fd_set *restrict readfds, fd_set *restrict writefds,
     readfds = &empty;
   if (writefds == NULL)
     writefds = &empty;
+  if (errorfds == NULL)
+    errorfds = &empty;
 
   // Determine the maximum number of events.
-  size_t maxevents = readfds->__nfds + writefds->__nfds + 1;
+  size_t maxevents = readfds->__nfds + writefds->__nfds + errorfds->__nfds + 1;
   __wasi_subscription_t subscriptions[maxevents];
   size_t nsubscriptions = 0;
 
@@ -64,6 +59,19 @@ int pselect(int nfds, fd_set *restrict readfds, fd_set *restrict writefds,
     }
   }
 
+  // Convert the errorfds set.
+  for (size_t i = 0; i < errorfds->__nfds; ++i) {
+    int fd = errorfds->__fds[i];
+    if (fd < nfds) {
+      __wasi_subscription_t *subscription = &subscriptions[nsubscriptions++];
+      *subscription = (__wasi_subscription_t){
+          .userdata = fd,
+          .u.tag = __WASI_EVENTTYPE_FD_EXCEPT,
+          .u.u.fd_read.file_descriptor = fd,
+      };
+    }
+  }
+
   // Create extra event for the timeout.
   if (timeout != NULL) {
     __wasi_subscription_t *subscription = &subscriptions[nsubscriptions++];
@@ -103,7 +111,8 @@ int pselect(int nfds, fd_set *restrict readfds, fd_set *restrict writefds,
   for (size_t i = 0; i < nevents; ++i) {
     const __wasi_event_t *event = &events[i];
     if ((event->type == __WASI_EVENTTYPE_FD_READ ||
-         event->type == __WASI_EVENTTYPE_FD_WRITE) &&
+         event->type == __WASI_EVENTTYPE_FD_WRITE ||
+         event->type == __WASI_EVENTTYPE_FD_EXCEPT) &&
         event->error == __WASI_ERRNO_BADF) {
       errno = EBADF;
       return -1;
@@ -113,13 +122,16 @@ int pselect(int nfds, fd_set *restrict readfds, fd_set *restrict writefds,
   // Clear and set entries in the result sets.
   FD_ZERO(readfds);
   FD_ZERO(writefds);
+  FD_ZERO(errorfds);
   for (size_t i = 0; i < nevents; ++i) {
     const __wasi_event_t *event = &events[i];
     if (event->type == __WASI_EVENTTYPE_FD_READ) {
       readfds->__fds[readfds->__nfds++] = event->userdata;
     } else if (event->type == __WASI_EVENTTYPE_FD_WRITE) {
       writefds->__fds[writefds->__nfds++] = event->userdata;
+    } else if (event->type == __WASI_EVENTTYPE_FD_EXCEPT) {
+      errorfds->__fds[errorfds->__nfds++] = event->userdata;
     }
   }
-  return readfds->__nfds + writefds->__nfds;
+  return readfds->__nfds + writefds->__nfds + errorfds->__nfds;
 }
diff --git a/libc-bottom-half/cloudlibc/src/libc/sys/socket/recv.c b/libc-bottom-half/cloudlibc/src/libc/sys/socket/recv.c
index e308b1469..0ea766d8c 100644
--- a/libc-bottom-half/cloudlibc/src/libc/sys/socket/recv.c
+++ b/libc-bottom-half/cloudlibc/src/libc/sys/socket/recv.c
@@ -21,6 +21,7 @@ ssize_t recv(int socket, void *restrict buffer, size_t length, int flags) {
   if ((flags & MSG_WAITALL) != 0) { ri_flags |= __WASI_RIFLAGS_RECV_WAITALL; }
   if ((flags & MSG_TRUNC) != 0) { ri_flags |= __WASI_RIFLAGS_RECV_DATA_TRUNCATED; }
   if ((flags & MSG_DONTWAIT) != 0) { ri_flags |= __WASI_RIFLAGS_RECV_DONT_WAIT; }
+  if ((flags & MSG_OOB) != 0) { ri_flags |= __WASI_RIFLAGS_RECV_OOB; }
 
   // Perform system call.
   __wasi_size_t ro_datalen;
diff --git a/libc-bottom-half/cloudlibc/src/libc/sys/socket/recvfrom.c b/libc-bottom-half/cloudlibc/src/libc/sys/socket/recvfrom.c
index c06e1e1b1..d73c787f5 100644
--- a/libc-bottom-half/cloudlibc/src/libc/sys/socket/recvfrom.c
+++ b/libc-bottom-half/cloudlibc/src/libc/sys/socket/recvfrom.c
@@ -20,6 +20,7 @@ ssize_t recvfrom(int socket, void* buffer, size_t length, int flags, struct sock
   if ((flags & MSG_WAITALL) != 0) { ri_flags |= __WASI_RIFLAGS_RECV_WAITALL; }
   if ((flags & MSG_TRUNC) != 0) { ri_flags |= __WASI_RIFLAGS_RECV_DATA_TRUNCATED; }
   if ((flags & MSG_DONTWAIT) != 0) { ri_flags |= __WASI_RIFLAGS_RECV_DONT_WAIT; }
+  if ((flags & MSG_OOB) != 0) { ri_flags |= __WASI_RIFLAGS_RECV_OOB; }
 
   // Perform system call.
   __wasi_size_t ro_datalen;
diff --git a/libc-bottom-half/cloudlibc/src/libc/sys/socket/recvmsg.c b/libc-bottom-half/cloudlibc/src/libc/sys/socket/recvmsg.c
index 74b404ead..ef5738aaa 100644
--- a/libc-bottom-half/cloudlibc/src/libc/sys/socket/recvmsg.c
+++ b/libc-bottom-half/cloudlibc/src/libc/sys/socket/recvmsg.c
@@ -18,6 +18,7 @@ ssize_t recvmsg(int socket, struct msghdr *restrict msg, int flags) {
   if ((flags & MSG_WAITALL) != 0) { ri_flags |= __WASI_RIFLAGS_RECV_WAITALL; }
   if ((flags & MSG_TRUNC) != 0) { ri_flags |= __WASI_RIFLAGS_RECV_DATA_TRUNCATED; }
   if ((flags & MSG_DONTWAIT) != 0) { ri_flags |= __WASI_RIFLAGS_RECV_DONT_WAIT; }
+  if ((flags & MSG_OOB) != 0) { ri_flags |= __WASI_RIFLAGS_RECV_OOB; }
 
   __wasi_size_t ro_datalen;
   __wasi_roflags_t ro_flags;
diff --git a/libc-bottom-half/cloudlibc/src/libc/sys/socket/send.c b/libc-bottom-half/cloudlibc/src/libc/sys/socket/send.c
index 3a2b657a7..89a5d247d 100644
--- a/libc-bottom-half/cloudlibc/src/libc/sys/socket/send.c
+++ b/libc-bottom-half/cloudlibc/src/libc/sys/socket/send.c
@@ -21,6 +21,7 @@ ssize_t send(int socket, const void *buffer, size_t length, int flags) {
   __wasi_siflags_t si_flags = 0;
 
   if ((flags & MSG_DONTWAIT) != 0) { si_flags |= __WASI_SIFLAGS_SEND_DONT_WAIT; }
+  if ((flags & MSG_OOB) != 0) { si_flags |= __WASI_SIFLAGS_SEND_OOB; }
 
   // Perform system call.
   __wasi_size_t so_datalen;
diff --git a/libc-bottom-half/cloudlibc/src/libc/sys/socket/sendmsg.c b/libc-bottom-half/cloudlibc/src/libc/sys/socket/sendmsg.c
index f161afed9..4457f1623 100644
--- a/libc-bottom-half/cloudlibc/src/libc/sys/socket/sendmsg.c
+++ b/libc-bottom-half/cloudlibc/src/libc/sys/socket/sendmsg.c
@@ -23,6 +23,7 @@ ssize_t sendmsg(int socket, const struct msghdr* msg, int flags) {
   __wasi_errno_t error;
 
   if ((flags & MSG_DONTWAIT) != 0) { si_flags |= __WASI_SIFLAGS_SEND_DONT_WAIT; }
+  if ((flags & MSG_OOB) != 0) { si_flags |= __WASI_SIFLAGS_SEND_OOB; }
 
   if (msg->msg_name == NULL) {
     error = __wasi_sock_send(socket, si_data, si_data_len, si_flags, &so_datalen);
diff --git a/libc-bottom-half/cloudlibc/src/libc/sys/socket/sendto.c b/libc-bottom-half/cloudlibc/src/libc/sys/socket/sendto.c
index 8b050d648..72a681159 100644
--- a/libc-bottom-half/cloudlibc/src/libc/sys/socket/sendto.c
+++ b/libc-bottom-half/cloudlibc/src/libc/sys/socket/sendto.c
@@ -21,6 +21,7 @@ ssize_t sendto(int socket, const void *restrict buffer, size_t length, int flags
   __wasi_siflags_t si_flags = 0;
 
   if ((flags & MSG_DONTWAIT) != 0) { si_flags |= __WASI_SIFLAGS_SEND_DONT_WAIT; }
+  if ((flags & MSG_OOB) != 0) { si_flags |= __WASI_SIFLAGS_SEND_OOB; }
 
   __wasi_addr_port_t peer_addr;
   __wasi_errno_t error = sockaddr_to_wasi(addr, addrlen, &peer_addr);
diff --git a/libc-bottom-half/headers/public/__header_poll.h b/libc-bottom-half/headers/public/__header_poll.h
index 23b36f2f2..232fd0864 100644
--- a/libc-bottom-half/headers/public/__header_poll.h
+++ b/libc-bottom-half/headers/public/__header_poll.h
@@ -6,6 +6,7 @@
 
 #define POLLRDNORM 0x1
 #define POLLWRNORM 0x2
+#define POLLPRI 0x4
 
 #define POLLIN POLLRDNORM
 #define POLLOUT POLLWRNORM
diff --git a/libc-bottom-half/headers/public/wasi/api_poly.h b/libc-bottom-half/headers/public/wasi/api_poly.h
index 8e8877f5c..37634f40b 100644
--- a/libc-bottom-half/headers/public/wasi/api_poly.h
+++ b/libc-bottom-half/headers/public/wasi/api_poly.h
@@ -4,6 +4,12 @@
 #include <stddef.h>
 #include <stdint.h>
 
+/**
+ * WASIX extension to the preview1 event type namespace. Indicates that a file
+ * descriptor has an exceptional condition pending, such as TCP urgent data.
+ */
+#define __WASI_EVENTTYPE_FD_EXCEPT (UINT8_C(3))
+
 #ifdef _REENTRANT
 /**
  * Request a new thread to be created by the host.
diff --git a/libc-bottom-half/headers/public/wasi/api_wasix.h b/libc-bottom-half/headers/public/wasi/api_wasix.h
index e43aa20c8..40ea1e8b3 100644
--- a/libc-bottom-half/headers/public/wasi/api_wasix.h
+++ b/libc-bottom-half/headers/public/wasi/api_wasix.h
@@ -765,6 +765,12 @@ typedef uint16_t __wasi_riflags_t;
  */
 #define __WASI_RIFLAGS_RECV_DONT_WAIT ((__wasi_riflags_t)+(1 << 3))
 
+/**
+ * Receive out-of-band (urgent) data. Only meaningful for stream sockets
+ * whose transport supports it (e.g. TCP).
+ */
+#define __WASI_RIFLAGS_RECV_OOB ((__wasi_riflags_t)+(1 << 4))
+
 /**
  * Signal condition.
  */
@@ -1414,6 +1420,12 @@ typedef uint16_t __wasi_siflags_t;
  */
 #define __WASI_SIFLAGS_SEND_DONT_WAIT ((__wasi_siflags_t)+(1 << 0))
 
+/**
+ * Send out-of-band (urgent) data. Only meaningful for stream sockets whose
+ * transport supports it (e.g. TCP).
+ */
+#define __WASI_SIFLAGS_SEND_OOB ((__wasi_siflags_t)+(1 << 1))
+
 /**
 *** Hidden type
 typedef uint8_t __wasi_sdflags_t;
diff --git a/libc-top-half/musl/include/poll.h b/libc-top-half/musl/include/poll.h
index cdd650e2b..cdbd29a21 100644
--- a/libc-top-half/musl/include/poll.h
+++ b/libc-top-half/musl/include/poll.h
@@ -28,10 +28,6 @@ extern "C" {
 #endif
 #else
 #include <__header_poll.h>
-// Poll fulfill. Since there are no important polls
-// we identify all Important as normals
-#define POLLPRI POLLIN
-#define EPOLLPRI EPOLLIN
 #endif
 
 #ifdef __wasilibc_unmodified_upstream /* Use alternate WASI libc headers */
diff --git a/result b/result
new file mode 120000
index 000000000..d025da318
--- /dev/null
+++ b/result
@@ -0,0 +1 @@
+/nix/store/jpajkzk1isciic6887rwizv26ssi1j5q-subxt-0.50.3
\ No newline at end of file
diff --git a/tools/wasix-headers/WASI b/tools/wasix-headers/WASI
index 0dfbd35a0..b7f2529fe 160000
--- a/tools/wasix-headers/WASI
+++ b/tools/wasix-headers/WASI
@@ -1 +1 @@
-Subproject commit 0dfbd35a0f30f3fe7fd3b3ab5a50dc4191d5caed
+Subproject commit b7f2529fe762eb2f83127f5374a0018292499a2b