diff --git a/stdlib/public/Platform/WASILibc.swift.gyb b/stdlib/public/Platform/WASILibc.swift.gyb
index a4379816ad69d..bd6e03ed3c4af 100644
--- a/stdlib/public/Platform/WASILibc.swift.gyb
+++ b/stdlib/public/Platform/WASILibc.swift.gyb
@@ -64,35 +64,98 @@ public let ${prefix}_TRUE_MIN = ${type}.leastNonzeroMagnitude
 
 public let MAP_FAILED: UnsafeMutableRawPointer! = UnsafeMutableRawPointer(bitPattern: -1)
 
-// wasi-libc's error.h uses a macro that Swift can't import.
-@available(*, deprecated, message: "Please use 'POSIXErrorCode.EACCES'.")
-public let EACCES: Int32 = 2
-@available(*, deprecated, message: "Please use 'POSIXErrorCode.EDQUOT'.")
-public let EDQUOT: Int32 = 19
-@available(*, deprecated, message: "Please use 'POSIXErrorCode.EEXIST'.")
-public let EEXIST: Int32 = 20
-@available(*, deprecated, message: "Please use 'POSIXErrorCode.EFBIG'.")
-public let EFBIG: Int32 = 22
-@available(*, deprecated, message: "Please use 'POSIXErrorCode.EINTR'.")
-public let EINTR: Int32 = 27
-@available(*, deprecated, message: "Please use 'POSIXErrorCode.EINVAL'.")
-public let EINVAL: Int32 = 28
-@available(*, deprecated, message: "Please use 'POSIXErrorCode.ENAMETOOLONG'.")
-public let ENAMETOOLONG: Int32 = 37
-@available(*, deprecated, message: "Please use 'POSIXErrorCode.ENOENT'.")
-public let ENOENT: Int32 = 44
-@available(*, deprecated, message: "Please use 'POSIXErrorCode.ENOSPC'.")
-public let ENOSPC: Int32 = 51
-@available(*, deprecated, message: "Please use 'POSIXErrorCode.EPERM'.")
-public let EPERM: Int32 = 63
-@available(*, deprecated, message: "Please use 'POSIXErrorCode.EROFS'.")
-public let EROFS: Int32 = 69
-
-
-// wasi-libc's _seek.h uses a macro that Swift can't import.
-// https://developer.apple.com/documentation/swift/using-imported-c-macros-in-swift
-// https://github.com/apple/swift/blob/c55b9cc87925c5d63a21d383ad23dff056d36607/lib/ClangImporter/ImportName.cpp#L2115-L2117
-// https://github.com/WebAssembly/wasi-libc/pull/148
+// TODO: wasi-libc's error.h defines these macros as function-like macros, which
+// Swift can't import for now.
+%{
+posix_error_codes = [
+  "E2BIG",
+  "EACCES",
+  "EADDRINUSE",
+  "EADDRNOTAVAIL",
+  "EAFNOSUPPORT",
+  "EAGAIN",
+  "EALREADY",
+  "EBADF",
+  "EBADMSG",
+  "EBUSY",
+  "ECANCELED",
+  "ECHILD",
+  "ECONNABORTED",
+  "ECONNREFUSED",
+  "ECONNRESET",
+  "EDEADLK",
+  "EDESTADDRREQ",
+  "EDOM",
+  "EDQUOT",
+  "EEXIST",
+  "EFAULT",
+  "EFBIG",
+  "EHOSTUNREACH",
+  "EIDRM",
+  "EILSEQ",
+  "EINPROGRESS",
+  "EINTR",
+  "EINVAL",
+  "EIO",
+  "EISCONN",
+  "EISDIR",
+  "ELOOP",
+  "EMFILE",
+  "EMLINK",
+  "EMSGSIZE",
+  "EMULTIHOP",
+  "ENAMETOOLONG",
+  "ENETDOWN",
+  "ENETRESET",
+  "ENETUNREACH",
+  "ENFILE",
+  "ENOBUFS",
+  "ENODEV",
+  "ENOENT",
+  "ENOEXEC",
+  "ENOLCK",
+  "ENOLINK",
+  "ENOMEM",
+  "ENOMSG",
+  "ENOPROTOOPT",
+  "ENOSPC",
+  "ENOSYS",
+  "ENOTCONN",
+  "ENOTDIR",
+  "ENOTEMPTY",
+  "ENOTRECOVERABLE",
+  "ENOTSOCK",
+  "ENOTSUP",
+  "ENOTTY",
+  "ENXIO",
+  "EOVERFLOW",
+  "EOWNERDEAD",
+  "EPERM",
+  "EPIPE",
+  "EPROTO",
+  "EPROTONOSUPPORT",
+  "EPROTOTYPE",
+  "ERANGE",
+  "EROFS",
+  "ESPIPE",
+  "ESRCH",
+  "ESTALE",
+  "ETIMEDOUT",
+  "ETXTBSY",
+  "EXDEV",
+  "ENOTCAPABLE",
+]
+}%
+
+%for ecode in posix_error_codes:
+
+@available(*, deprecated, message: "Please use 'POSIXErrorCode.${ecode}'.")
+public let ${ecode} = POSIXErrorCode.${ecode}.rawValue
+
+%end
+
+// TODO: wasi-libc's _seek.h defines these macros as function-like macros, which
+// Swift can't import for now.
 public let SEEK_SET: Int32 = 0
 public let SEEK_CUR: Int32 = 1
 public let SEEK_END: Int32 = 2