diff --git a/man2/outb.2 b/man2/outb.2
index df6449faa..d497c53b3 100644
--- a/man2/outb.2
+++ b/man2/outb.2
@@ -25,11 +25,43 @@
 .\" USA.
 .\"
 .\"
-.TH OUTB 2 1995-11-29 "Linux" "Linux Programmer's Manual"
+.TH OUTB 2 2012-12-31 "Linux" "Linux Programmer's Manual"
 .SH NAME
 outb, outw, outl, outsb, outsw, outsl,
 inb, inw, inl, insb, insw, insl,
 outb_p, outw_p, outl_p, inb_p, inw_p, inl_p \- port I/O
+.SH SYNOPSIS
+.nf
+.B #include <sys/io.h>
+
+
+.BI "unsigned char inb(unsigned short int " port );
+.BI "unsigned char inb_p(unsigned short int " port );
+.BI "unsigned short int inw(unsigned short int " port );
+.BI "unsigned short int inw_p(unsigned short int " port );
+.BI "unsigned int inl(unsigned short int " port );
+.BI "unsigned int inl_p(unsigned short int " port );
+
+.BI "void outb(unsigned char " value ", unsigned short int " port );
+.BI "void outb_p(unsigned char " value ", unsigned short int " port );
+.BI "void outw(unsigned short int " value ", unsigned short int " port );
+.BI "void outw_p(unsigned short int " value ", unsigned short int " port );
+.BI "void outl(unsigned int " value ", unsigned short int " port );
+.BI "void outl_p(unsigned int " value ", unsigned short int " port );
+
+.BI "void insb(unsigned short int " port ", void *" addr ,
+.BI "           unsigned long int " count );
+.BI "void insw(unsigned short int " port ", void *" addr ,
+.BI "           unsigned long int " count );
+.BI "void insl(unsigned short int " port ", void *" addr ,
+.BI "           unsigned long int " count );
+.BI "void outsb(unsigned short int " port ", const void *" addr ,
+.BI "           unsigned long int " count );
+.BI "void outsw(unsigned short int " port ", const void *" addr ,
+.BI "           unsigned long int " count );
+.BI "void outsl(unsigned short int " port ", const void *" addr ,
+.BI "           unsigned long int " count );
+.fi
 .SH DESCRIPTION
 This family of functions is used to do low-level port input and output.
 The out* functions do port output, the in* functions do port input;