diff --git a/core/sys/linux/constants.odin b/core/sys/linux/constants.odin
index 6294602e9..ecd630fa9 100644
--- a/core/sys/linux/constants.odin
+++ b/core/sys/linux/constants.odin
@@ -1,6 +1,21 @@
 
 package linux
 
+/*
+	Standard input file descriptor
+*/
+STDIN_FILENO :: Fd(0)
+
+/*
+	Standard output file descriptor
+*/
+STDOUT_FILENO :: Fd(1)
+
+/*
+	Standard output file descriptor
+*/
+STDERR_FILENO :: Fd(2)
+
 /*
 	Special file descriptor to pass to `*at` functions to specify
 	that relative paths are relative to current directory.
diff --git a/core/sys/linux/sys.odin b/core/sys/linux/sys.odin
index 9a0f18e9f..7bec8eee2 100644
--- a/core/sys/linux/sys.odin
+++ b/core/sys/linux/sys.odin
@@ -216,7 +216,17 @@ rt_sigprocmask :: proc "contextless" (mask_kind: Sig_Mask_Kind, new_set: ^Sig_Se
 	return Errno(-ret)
 }
 
-// TODO(flysand): ioctl
+/*
+	Control devices. The ioctl syscall is a bit special because
+	its argument is usually a pointer to some driver-specific structure.
+	The request value is device-specific. Consult your LibC implementation's
+	ioctls.h file to learn more.
+	Available since Linux 1.0.
+*/
+ioctl :: proc "contextless" (fd: Fd, request: u64, arg: u64) -> (Errno) {
+	ret := syscall(SYS_ioctl, fd, request, arg)
+	return Errno(-ret)
+}
 
 /*
 	Read the file at a specified offset.