diff --git a/man2/modify_ldt.2 b/man2/modify_ldt.2
index 8c5d99c50..30ba3018b 100644
--- a/man2/modify_ldt.2
+++ b/man2/modify_ldt.2
@@ -54,10 +54,39 @@ is 1,
 modifies one ldt entry.
 .I ptr
 points to a
-.I modify_ldt_ldt_s
-structure and
+.I user_desc
+structure
+and
 .I bytecount
 must equal the size of this structure.
+.\"
+.\" FIXME, say something about func == 2 ans func == 0x11?
+.\" In Linux 2.4, func == 2 returned "the default ldt"
+.\" In Linux 2.6, func == 2 is a nop, returning a zeroed out structure.
+.\" Linux 2.4 and 2.6 implement an operation for func == 0x11
+
+The
+.I user_desc
+structure is defined in <asm/ldt.h> as:
+.in +0.25i
+.nf
+
+struct user_desc {
+    unsigned int  entry_number;
+    unsigned long base_addr;
+    unsigned int  limit;
+    unsigned int  seg_32bit:1;
+    unsigned int  contents:2;
+    unsigned int  read_exec_only:1;
+    unsigned int  limit_in_pages:1;
+    unsigned int  seg_not_present:1;
+    unsigned int  useable:1;
+};
+.fi
+.in
+.PP
+In Linux 2.4 and earlier, this structure was named
+.IR modify_ldt_ldt_s .
 .\" .PP
 .\" The ldt is specific for the calling process. Any attempts to change
 .\" the ldt to include the address space of another process or the kernel
@@ -72,7 +101,8 @@ or 0 (for writing).
 On failure,
 .BR modify_ldt ()
 returns \-1 and sets
-.IR errno .
+.IR errno
+to indicate the error.
 .SH ERRORS
 .TP
 .B EFAULT