diff --git a/pqsort.c b/pqsort.c
index c49d077e..8e2b1248 100644
--- a/pqsort.c
+++ b/pqsort.c
@@ -37,6 +37,8 @@
  * SUCH DAMAGE.
  */
 
+#define __P(protos) protos
+
 #include <sys/cdefs.h>
 #if defined(LIBC_SCCS) && !defined(lint)
 #if 0
diff --git a/redis.conf b/redis.conf
index e7b5b9d0..8a962f4a 100644
--- a/redis.conf
+++ b/redis.conf
@@ -97,6 +97,13 @@ databases 16
 # If all this fails, Redis will start to reply with errors to commands
 # that will use more memory, like SET, LPUSH, and so on, and will continue
 # to reply to most read-only commands like GET.
+#
+# WARNING: maxmemory can be a good idea mainly if you want to use Redis as a
+# 'state' server or cache, not as a real DB. When Redis is used as a real
+# database the memory usage will grow over the weeks, it will be obvious if
+# it is going to use too much memory in the long run, and you'll have the time
+# to upgrade. With maxmemory after the limit is reached you'll start to get
+# errors for write operations, and this may even lead to DB inconsistency.
 
 # maxmemory <bytes>