Adapted from https://github.com/antirez/redis/commit/e6f39338e6464fb29f630120d8949b0d535e2e3f.patch

--- src/config.c.orig	2014-12-16 03:18:20.000000000 -0500
+++ src/config.c	2016-09-30 16:25:06.586589235 -0400
@@ -49,7 +49,7 @@
     {NULL, 0}
 };
 
-clientBufferLimitsConfig clientBufferLimitsDefaults[REDIS_CLIENT_TYPE_COUNT] = {
+clientBufferLimitsConfig clientBufferLimitsDefaults[REDIS_CLIENT_TYPE_OBUF_COUNT] = {
     {0, 0, 0}, /* normal */
     {1024*1024*256, 1024*1024*64, 60}, /* slave */
     {1024*1024*32, 1024*1024*8, 60}  /* pubsub */
@@ -1105,13 +1105,13 @@
         sds buf = sdsempty();
         int j;
 
-        for (j = 0; j < REDIS_CLIENT_TYPE_COUNT; j++) {
+        for (j = 0; j < REDIS_CLIENT_TYPE_OBUF_COUNT; j++) {
             buf = sdscatprintf(buf,"%s %llu %llu %ld",
                     getClientTypeName(j),
                     server.client_obuf_limits[j].hard_limit_bytes,
                     server.client_obuf_limits[j].soft_limit_bytes,
                     (long) server.client_obuf_limits[j].soft_limit_seconds);
-            if (j != REDIS_CLIENT_TYPE_COUNT-1)
+            if (j != REDIS_CLIENT_TYPE_OBUF_COUNT-1)
                 buf = sdscatlen(buf," ",1);
         }
         addReplyBulkCString(c,"client-output-buffer-limit");
@@ -1526,7 +1526,7 @@
     int j;
     char *option = "client-output-buffer-limit";
 
-    for (j = 0; j < REDIS_CLIENT_TYPE_COUNT; j++) {
+    for (j = 0; j < REDIS_CLIENT_TYPE_OBUF_COUNT; j++) {
         int force = (server.client_obuf_limits[j].hard_limit_bytes !=
                     clientBufferLimitsDefaults[j].hard_limit_bytes) ||
                     (server.client_obuf_limits[j].soft_limit_bytes !=
--- src/networking.c.orig	2014-12-16 03:18:20.000000000 -0500
+++ src/networking.c	2016-09-30 16:37:53.980349749 -0400
@@ -1526,12 +1526,13 @@
  * REDIS_CLIENT_TYPE_NORMAL -> Normal client
  * REDIS_CLIENT_TYPE_SLAVE  -> Slave or client executing MONITOR command
  * REDIS_CLIENT_TYPE_PUBSUB -> Client subscribed to Pub/Sub channels
+ * REDIS_CLIENT_TYPE_MASTER -> The client representing our replication master.
  */
 int getClientType(redisClient *c) {
+    if (c->flags & REDIS_MASTER) return REDIS_CLIENT_TYPE_MASTER;
     if ((c->flags & REDIS_SLAVE) && !(c->flags & REDIS_MONITOR))
         return REDIS_CLIENT_TYPE_SLAVE;
-    if (c->flags & REDIS_PUBSUB)
-        return REDIS_CLIENT_TYPE_PUBSUB;
+    if (c->flags & REDIS_PUBSUB) return REDIS_CLIENT_TYPE_PUBSUB;
     return REDIS_CLIENT_TYPE_NORMAL;
 }
 
@@ -1539,6 +1540,7 @@
     if (!strcasecmp(name,"normal")) return REDIS_CLIENT_TYPE_NORMAL;
     else if (!strcasecmp(name,"slave")) return REDIS_CLIENT_TYPE_SLAVE;
     else if (!strcasecmp(name,"pubsub")) return REDIS_CLIENT_TYPE_PUBSUB;
+    else if (!strcasecmp(name,"master")) return REDIS_CLIENT_TYPE_MASTER;
     else return -1;
 }
 
@@ -1547,6 +1549,7 @@
     case REDIS_CLIENT_TYPE_NORMAL: return "normal";
     case REDIS_CLIENT_TYPE_SLAVE:  return "slave";
     case REDIS_CLIENT_TYPE_PUBSUB: return "pubsub";
+    case REDIS_CLIENT_TYPE_MASTER: return "master";
     default:                       return NULL;
     }
 }
@@ -1562,6 +1565,10 @@
     unsigned long used_mem = getClientOutputBufferMemoryUsage(c);
 
     class = getClientType(c);
+    /* For the purpose of output buffer limiting, masters are handled
+     * like normal clients. */
+    if (class == REDIS_CLIENT_TYPE_MASTER) class = REDIS_CLIENT_TYPE_NORMAL;
+
     if (server.client_obuf_limits[class].hard_limit_bytes &&
         used_mem >= server.client_obuf_limits[class].hard_limit_bytes)
         hard = 1;
--- src/redis.h.orig	2014-12-16 03:18:20.000000000 -0500
+++ src/redis.h	2016-09-30 16:29:11.324284488 -0400
@@ -261,7 +261,10 @@
 #define REDIS_CLIENT_TYPE_NORMAL 0 /* Normal req-reply clients + MONITORs */
 #define REDIS_CLIENT_TYPE_SLAVE 1  /* Slaves. */
 #define REDIS_CLIENT_TYPE_PUBSUB 2 /* Clients subscribed to PubSub channels. */
-#define REDIS_CLIENT_TYPE_COUNT 3
+#define REDIS_CLIENT_TYPE_MASTER 3 /* Master. */
+#define REDIS_CLIENT_TYPE_OBUF_COUNT 3 /* Number of clients to expose to output
+                                          buffer configuration. Just the first
+                                          three: normal, slave, pubsub. */
 
 /* Slave replication state - from the point of view of the slave. */
 #define REDIS_REPL_NONE 0 /* No active replication */
@@ -569,7 +572,7 @@
     time_t soft_limit_seconds;
 } clientBufferLimitsConfig;
 
-extern clientBufferLimitsConfig clientBufferLimitsDefaults[REDIS_CLIENT_TYPE_COUNT];
+extern clientBufferLimitsConfig clientBufferLimitsDefaults[REDIS_CLIENT_TYPE_OBUF_COUNT];
 
 /* The redisOp structure defines a Redis Operation, that is an instance of
  * a command with an argument vector, database ID, propagation target
@@ -685,7 +688,7 @@
     size_t client_max_querybuf_len; /* Limit for client query buffer length */
     int dbnum;                      /* Total number of configured DBs */
     int daemonize;                  /* True if running as a daemon */
-    clientBufferLimitsConfig client_obuf_limits[REDIS_CLIENT_TYPE_COUNT];
+    clientBufferLimitsConfig client_obuf_limits[REDIS_CLIENT_TYPE_OBUF_COUNT];
     /* AOF persistence */
     int aof_state;                  /* REDIS_AOF_(ON|OFF|WAIT_REWRITE) */
     int aof_fsync;                  /* Kind of fsync() policy */
--- src/redis.c.orig	2014-12-16 03:18:20.000000000 -0500
+++ src/redis.c	2016-09-30 16:28:51.135397850 -0400
@@ -1419,7 +1419,7 @@
     server.repl_no_slaves_since = time(NULL);
 
     /* Client output buffer limits */
-    for (j = 0; j < REDIS_CLIENT_TYPE_COUNT; j++)
+    for (j = 0; j < REDIS_CLIENT_TYPE_OBUF_COUNT; j++)
         server.client_obuf_limits[j] = clientBufferLimitsDefaults[j];
 
     /* Double constants initialization */