diff --git a/src/Makefile b/src/Makefile
index 93cfdc28e..1c80e547f 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -20,7 +20,7 @@ DEPENDENCY_TARGETS=hiredis linenoise lua
 NODEPS:=clean distclean
 
 # Default settings
-STD=-std=c99 -pedantic -DREDIS_STATIC=''
+1TD=-std=c11 -pedantic -DREDIS_STATIC=''
 ifneq (,$(findstring clang,$(CC)))
 ifneq (,$(findstring FreeBSD,$(uname_S)))
   STD+=-Wno-c11-extensions
diff --git a/src/networking.c b/src/networking.c
index 17d6b1866..d61e1f044 100644
--- a/src/networking.c
+++ b/src/networking.c
@@ -2527,7 +2527,7 @@ void *IOThreadMain(void *myid) {
 void initThreadedIO(void) {
     pthread_t tid;
 
-    server.io_threads_num = 4;
+    server.io_threads_num = 8;
     io_threads_active = 0; /* We start with threads not active. */
     for (int i = 0; i < server.io_threads_num; i++) {
         pthread_mutex_init(&io_threads_mutex[i],NULL);
@@ -2543,6 +2543,7 @@ void initThreadedIO(void) {
 }
 
 void startThreadedIO(void) {
+    printf("S"); fflush(stdout);
     if (tio_debug) printf("--- STARTING THREADED IO ---\n");
     serverAssert(io_threads_active == 0);
     for (int j = 0; j < server.io_threads_num; j++)
@@ -2551,6 +2552,7 @@ void startThreadedIO(void) {
 }
 
 void stopThreadedIO(void) {
+    printf("E"); fflush(stdout);
     if (tio_debug) printf("--- STOPPING THREADED IO ---\n");
     serverAssert(io_threads_active == 1);
     for (int j = 0; j < server.io_threads_num; j++)
@@ -2558,19 +2560,36 @@ void stopThreadedIO(void) {
     io_threads_active = 0;
 }
 
+/* This function checks if there are not enough pending clients to justify
+ * taking the I/O threads active: in that case I/O threads are stopped if
+ * currently active.
+ *
+ * The function returns 0 if the I/O threading should be used becuase there
+ * are enough active threads, otherwise 1 is returned and the I/O threads
+ * could be possibly stopped (if already active) as a side effect. */
+int stopThreadedIOIfNeeded(void) {
+    int pending = listLength(server.clients_pending_write);
+    if (pending < (server.io_threads_num*2)) {
+        if (io_threads_active) stopThreadedIO();
+        return 1;
+    } else {
+        return 0;
+    }
+}
+
 int handleClientsWithPendingWritesUsingThreads(void) {
     int processed = listLength(server.clients_pending_write);
     if (processed == 0) return 0; /* Return ASAP if there are no clients. */
 
     /* If we have just a few clients to serve, don't use I/O threads, but the
      * boring synchronous code. */
-    if (processed < (server.io_threads_num*2)) {
-        if (io_threads_active) stopThreadedIO();
+    if (stopThreadedIOIfNeeded()) {
         return handleClientsWithPendingWrites();
-    } else {
-        if (!io_threads_active) startThreadedIO();
     }
 
+    /* Start threads if needed. */
+    if (!io_threads_active) startThreadedIO();
+
     if (tio_debug) printf("%d TOTAL pending clients\n", processed);
 
     /* Distribute the clients across N different lists. */
diff --git a/src/server.c b/src/server.c
index de5a814d0..325c9010c 100644
--- a/src/server.c
+++ b/src/server.c
@@ -2001,6 +2001,9 @@ int serverCron(struct aeEventLoop *eventLoop, long long id, void *clientData) {
         migrateCloseTimedoutSockets();
     }
 
+    /* Stop the I/O threads if we don't have enough pending work. */
+    stopThreadedIOIfNeeded();
+
     /* Start a scheduled BGSAVE if the corresponding flag is set. This is
      * useful when we are forced to postpone a BGSAVE because an AOF
      * rewrite is in progress.
diff --git a/src/server.h b/src/server.h
index d2a563c96..96ee37887 100644
--- a/src/server.h
+++ b/src/server.h
@@ -1579,6 +1579,7 @@ int clientsArePaused(void);
 int processEventsWhileBlocked(void);
 int handleClientsWithPendingWrites(void);
 int handleClientsWithPendingWritesUsingThreads(void);
+int stopThreadedIOIfNeeded(void);
 int clientHasPendingReplies(client *c);
 void unlinkClient(client *c);
 int writeToClient(int fd, client *c, int handler_installed);