diff --git a/Changes b/Changes
index 321c2bb2f..412baa440 100644
--- a/Changes
+++ b/Changes
@@ -2236,3 +2236,5 @@ seen. gmtime warning still there
   is disabled by default at newer *BSD versions. Also improved another warning.
 - Added set::channel-command-prefix to allow channel text which starts with specific characters
   to be sent to +d clients (for in channel commands).
+- Added a README
+- Added some checking in fdlist add/remove functions.
diff --git a/README b/README
new file mode 100644
index 000000000..d8edfebc5
--- /dev/null
+++ b/README
@@ -0,0 +1,24 @@
+==[ COMPILING ]==
+To build the ircd, run:
+./Config
+make
+
+If you specified an alternative location during ./Config you also need
+to run "make install".
+
+==[ MAKING A CONFIG FILE ]==
+If you are new, then you need to create your own configfile:
+
+copy doc/example.conf to your main UnrealIRCd directory and call
+it unrealircd.conf .
+Then open it in an editor and carefully modify it, consult the docs
+(doc/unreal32docs.html, or online: www.unrealircd.com/unreal32docs.html)
+for more information about every block/setting.
+Common problems are explained in the FAQ, which is located at:
+http://www.vulnscan.org/UnrealIrcd/faq/ .
+
+==[ BOOTING YOUR IRCD ]==
+Just type: ./unreal start
+Note that after booting the errors are usually logged to ircd.log,
+so check that file if you have any problems.
+Again, check the FAQ (and docs) if you have any boot problems.
diff --git a/src/fdlist.c b/src/fdlist.c
index f6c939516..4cac34f65 100644
--- a/src/fdlist.c
+++ b/src/fdlist.c
@@ -27,10 +27,27 @@
 #include "fdlist.h"
 #include <string.h>
 
+extern fdlist default_fdlist;
+extern fdlist busycli_fdlist;
+extern fdlist serv_fdlist;
+extern fdlist oper_fdlist;
+
 void addto_fdlist(int fd, fdlist * listp)
 {
 	int  index;
 
+	/* I prefer this little 5-cpu-cycles-check over memory corruption. -- Syzop */
+	if ((fd < 0) || (fd >= MAXCONNECTIONS))
+	{
+		sendto_realops("[BUG] trying to add fd #%d to 0x%x (%x/%x/%x/%x), range is 0..%d",
+			fd, listp, &default_fdlist, &busycli_fdlist, &serv_fdlist, &oper_fdlist,
+			MAXCONNECTIONS);
+		ircd_log(LOG_ERROR, "[BUG] trying to add fd #%d to 0x%x (%x/%x/%x/%x), range is 0..%d",
+			fd, listp, &default_fdlist, &busycli_fdlist, &serv_fdlist, &oper_fdlist,
+			MAXCONNECTIONS);
+		return;
+	}
+
 	if ((index = ++listp->last_entry) >= MAXCONNECTIONS)
 	{
 		/*
@@ -49,6 +66,18 @@ void delfrom_fdlist(int fd, fdlist * listp)
 {
 	int  i;
 
+	/* I prefer this little 5-cpu-cycles-check over memory corruption. -- Syzop */
+	if ((fd < 0) || (fd >= MAXCONNECTIONS))
+	{
+		sendto_realops("[BUG] trying to remove fd #%d to 0x%x (%x/%x/%x/%x), range is 0..%d",
+			fd, listp, &default_fdlist, &busycli_fdlist, &serv_fdlist, &oper_fdlist,
+			MAXCONNECTIONS);
+		ircd_log(LOG_ERROR, "[BUG] trying to remove fd #%d to 0x%x (%x/%x/%x/%x), range is 0..%d",
+			fd, listp, &default_fdlist, &busycli_fdlist, &serv_fdlist, &oper_fdlist,
+			MAXCONNECTIONS);
+		return;
+	}
+
 	for (i = listp->last_entry; i; i--)
 	{
 		if (listp->entry[i] == fd)