diff --git a/contrib/pypy/uwsgi_pypy_greenlets.py b/contrib/pypy/uwsgi_pypy_greenlets.py
index f915caf2..7843f177 100644
--- a/contrib/pypy/uwsgi_pypy_greenlets.py
+++ b/contrib/pypy/uwsgi_pypy_greenlets.py
@@ -54,7 +54,7 @@ def uwsgi_pypy_greenlet_switch(wsgi_req):
     # update current running greenlet
     lib.uwsgi.wsgi_req = wsgi_req
 
-if lib.uwsgi.async <= 1:
+if lib.uwsgi.async < 1:
     raise Exception("pypy greenlets require async mode !!!")
 lib.uwsgi.schedule_to_main = uwsgi_pypy_greenlet_switch
 lib.uwsgi.schedule_to_req = uwsgi_pypy_greenlet_schedule
diff --git a/core/async.c b/core/async.c
index dc87ae22..b4d342c6 100644
--- a/core/async.c
+++ b/core/async.c
@@ -165,7 +165,7 @@ static void async_expire_timeouts(uint64_t now) {
 
 int async_add_fd_read(struct wsgi_request *wsgi_req, int fd, int timeout) {
 
-	if (uwsgi.async < 2 || !uwsgi.async_waiting_fd_table){ 
+	if (uwsgi.async < 1 || !uwsgi.async_waiting_fd_table){ 
 		uwsgi_log_verbose("ASYNC call without async mode !!!\n");
 		return -1;
 	}
@@ -257,7 +257,7 @@ static int async_wait_fd_read2(int fd0, int fd1, int timeout, int *fd) {
 
 void async_add_timeout(struct wsgi_request *wsgi_req, int timeout) {
 
-	if (uwsgi.async < 2 || !uwsgi.rb_async_timeouts) {
+	if (uwsgi.async < 1 || !uwsgi.rb_async_timeouts) {
 		uwsgi_log_verbose("ASYNC call without async mode !!!\n");
 		return;
 	}
@@ -272,7 +272,7 @@ void async_add_timeout(struct wsgi_request *wsgi_req, int timeout) {
 
 int async_add_fd_write(struct wsgi_request *wsgi_req, int fd, int timeout) {
 
-	if (uwsgi.async < 2 || !uwsgi.async_waiting_fd_table) {
+	if (uwsgi.async < 1 || !uwsgi.async_waiting_fd_table) {
 		uwsgi_log_verbose("ASYNC call without async mode !!!\n");
 		return -1;
 	}
@@ -406,7 +406,7 @@ static int uwsgi_async_wait_milliseconds_hook(int timeout) {
 
 void async_loop() {
 
-	if (uwsgi.async < 2) {
+	if (uwsgi.async < 1) {
 		uwsgi_log("the async loop engine requires async mode (--async <n>)\n");
 		exit(1);
 	}
diff --git a/core/init.c b/core/init.c
index 09421bca..940e78d7 100644
--- a/core/init.c
+++ b/core/init.c
@@ -106,7 +106,7 @@ void uwsgi_init_default() {
 
 	uwsgi.forkbomb_delay = 2;
 
-	uwsgi.async = 1;
+	uwsgi.async = 0;
 	uwsgi.listen_queue = 100;
 
 	uwsgi.cheaper_overload = 3;
@@ -419,7 +419,7 @@ pid_t uwsgi_daemonize2() {
 // fix/check related options
 void sanitize_args() {
 
-        if (uwsgi.async > 1) {
+        if (uwsgi.async > 0) {
                 uwsgi.cores = uwsgi.async;
         }
 
diff --git a/core/uwsgi.c b/core/uwsgi.c
index ae9d2f83..1a9abb88 100644
--- a/core/uwsgi.c
+++ b/core/uwsgi.c
@@ -1228,7 +1228,7 @@ void gracefully_kill(int signum) {
 	}
 
 	// still not found a way to gracefully reload in async mode
-	if (uwsgi.async > 1) {
+	if (uwsgi.async > 0) {
 		exit(UWSGI_RELOAD_CODE);
 	}
 
@@ -2669,7 +2669,7 @@ int uwsgi_start(void *v_argv) {
 		}
 	}
 
-	if (uwsgi.async > 1) {
+	if (uwsgi.async > 0) {
 		if ((unsigned long) uwsgi.max_fd < (unsigned long) uwsgi.async) {
 			uwsgi_log_initial("- your current max open files limit is %lu, this is lower than requested async cores !!! -\n", (unsigned long) uwsgi.max_fd);
 			uwsgi.rl.rlim_cur = uwsgi.async;
@@ -2977,7 +2977,7 @@ unsafe:
 			uwsgi_log("*** Operational MODE: threaded ***\n");
 		}
 	}
-	else if (uwsgi.async > 1) {
+	else if (uwsgi.async > 0) {
 		if (uwsgi.numproc > 1) {
 			uwsgi_log("*** Operational MODE: preforking+async ***\n");
 		}
@@ -3345,7 +3345,7 @@ void uwsgi_worker_run() {
 	// some apps could be mounted only on specific workers
 	uwsgi_init_worker_mount_apps();
 
-	if (uwsgi.async > 1) {
+	if (uwsgi.async > 0) {
 		// a stack of unused cores
         	uwsgi.async_queue_unused = uwsgi_malloc(sizeof(struct wsgi_request *) * uwsgi.async);
 
@@ -3485,7 +3485,7 @@ void uwsgi_ignition() {
 		uwsgi_log("your loop engine died. R.I.P.\n");
 	}
 	else {
-		if (uwsgi.async < 2) {
+		if (uwsgi.async < 1) {
 			simple_loop();
 		}
 		else {
diff --git a/plugins/asyncio/asyncio.c b/plugins/asyncio/asyncio.c
index a5252307..6a6aab1e 100644
--- a/plugins/asyncio/asyncio.c
+++ b/plugins/asyncio/asyncio.c
@@ -314,7 +314,7 @@ static void asyncio_loop() {
 
 	uwsgi.schedule_fix = uwsgi_asyncio_schedule_fix;
 
-	if (uwsgi.async < 2) {
+	if (uwsgi.async < 1) {
 		uwsgi_log("the asyncio loop engine requires async mode (--async <n>)\n");
 		exit(1);
 	}
diff --git a/plugins/cgi/cgi_plugin.c b/plugins/cgi/cgi_plugin.c
index 2dcaa90e..d343d59f 100644
--- a/plugins/cgi/cgi_plugin.c
+++ b/plugins/cgi/cgi_plugin.c
@@ -731,7 +731,7 @@ clear2:
 
 		// now wait for process exit/death
 		// in async mode we need a trick...
-		if (uwsgi.async > 1) {
+		if (uwsgi.async > 0) {
 			pid_t diedpid = waitpid(cgi_pid, &waitpid_status, WNOHANG);
 			if (diedpid < 0) {
                                	uwsgi_error("waitpid()");
diff --git a/plugins/coroae/coroae.c b/plugins/coroae/coroae.c
index 2113a743..837f0543 100644
--- a/plugins/coroae/coroae.c
+++ b/plugins/coroae/coroae.c
@@ -356,7 +356,7 @@ static void coroae_wait_condvar(SV *cv) {
 
 static void coroae_loop() {
 
-	if (uwsgi.async < 2) {
+	if (uwsgi.async < 1) {
 		if (uwsgi.mywid == 1) {
 			uwsgi_log("the Coro::AnyEvent loop engine requires async mode (--async <n>)\n");
 		}
diff --git a/plugins/fiber/fiber.c b/plugins/fiber/fiber.c
index ca9191eb..30603ae0 100644
--- a/plugins/fiber/fiber.c
+++ b/plugins/fiber/fiber.c
@@ -83,7 +83,7 @@ static int fiber_init() {
 static void fiber_init_apps(void) {
 
         if (!ufiber.enabled) return;
-	if (uwsgi.async <= 1) {
+	if (uwsgi.async < 1) {
 		uwsgi_log("the fiber loop engine requires async mode\n");
 		exit(1);
 	}
diff --git a/plugins/gevent/gevent.c b/plugins/gevent/gevent.c
index 099bfc91..e8cd3875 100644
--- a/plugins/gevent/gevent.c
+++ b/plugins/gevent/gevent.c
@@ -368,7 +368,7 @@ static void gevent_loop() {
 
 	struct uwsgi_socket *uwsgi_sock = uwsgi.sockets;
 
-	if (uwsgi.async < 2) {
+	if (uwsgi.async < 1) {
 		uwsgi_log("the gevent loop engine requires async mode (--async <n>)\n");
 		exit(1);
 	}
diff --git a/plugins/glusterfs/glusterfs.c b/plugins/glusterfs/glusterfs.c
index 92616b6c..33f0ddfc 100644
--- a/plugins/glusterfs/glusterfs.c
+++ b/plugins/glusterfs/glusterfs.c
@@ -270,7 +270,7 @@ static int uwsgi_glusterfs_request(struct wsgi_request *wsgi_req) {
 	// skip body on HEAD
 	if (uwsgi_strncmp(wsgi_req->method, wsgi_req->method_len, "HEAD", 4)) {
 		size_t remains = st.st_size;
-		if (uwsgi.async > 1) {
+		if (uwsgi.async > 0) {
 			if (uwsgi_glusterfs_read_async(wsgi_req, fd, remains)) goto end;
 		}
 		else {
diff --git a/plugins/greenlet/greenlet.c b/plugins/greenlet/greenlet.c
index f494a3b5..7c69fa8e 100644
--- a/plugins/greenlet/greenlet.c
+++ b/plugins/greenlet/greenlet.c
@@ -116,7 +116,7 @@ static void greenlet_init_apps(void) {
 
 	if (!ugl.enabled) return;
 
-	if (uwsgi.async <= 1) {
+	if (uwsgi.async < 1) {
                 uwsgi_log("the greenlet suspend engine requires async mode\n");
                 exit(1);
         }
diff --git a/plugins/lua/lua_plugin.c b/plugins/lua/lua_plugin.c
index fe810457..0bd96a7e 100644
--- a/plugins/lua/lua_plugin.c
+++ b/plugins/lua/lua_plugin.c
@@ -843,7 +843,7 @@ static int uwsgi_lua_request(struct wsgi_request *wsgi_req) {
 		}
 		lua_pop(L, 1);
 		lua_pushvalue(L, -1);
-		if (uwsgi.async > 1) {
+		if (uwsgi.async > 0) {
 			return UWSGI_AGAIN;
 		}
 	}
diff --git a/plugins/psgi/psgi_plugin.c b/plugins/psgi/psgi_plugin.c
index a7c46026..4fb6de91 100644
--- a/plugins/psgi/psgi_plugin.c
+++ b/plugins/psgi/psgi_plugin.c
@@ -405,7 +405,7 @@ SV *build_psgi_env(struct wsgi_request *wsgi_req) {
 
         if (!hv_store(env, "psgi.run_once", 13, newSViv(0), 0)) goto clear;
 
-        if (uwsgi.async > 1) {
+        if (uwsgi.async > 0) {
                 if (!hv_store(env, "psgi.nonblocking", 16, newSViv(1), 0)) goto clear;
         }
         else {
@@ -631,7 +631,7 @@ int uwsgi_perl_request(struct wsgi_request *wsgi_req) {
 	}
 
 	while (psgi_response(wsgi_req, wsgi_req->async_result) != UWSGI_OK) {
-		if (uwsgi.async > 1) {
+		if (uwsgi.async > 0) {
 			FREETMPS;
 			LEAVE;
 			return UWSGI_AGAIN;
@@ -861,7 +861,7 @@ static void uwsgi_perl_atexit() {
                 return;
 
         // managing atexit in async mode is a real pain...skip it for now
-        if (uwsgi.async > 1)
+        if (uwsgi.async > 0)
                 return;
 realstuff:
 
diff --git a/plugins/psgi/psgi_response.c b/plugins/psgi/psgi_response.c
index e20cfc4d..b5c5614f 100644
--- a/plugins/psgi/psgi_response.c
+++ b/plugins/psgi/psgi_response.c
@@ -148,7 +148,7 @@ int psgi_response(struct wsgi_request *wsgi_req, AV *response) {
                         chitem = SvPV( chunk, hlen);
                         if (hlen <= 0) {
 				SvREFCNT_dec(chunk);
-				if (uwsgi.async > 1 && wsgi_req->async_force_again) {
+				if (uwsgi.async > 0 && wsgi_req->async_force_again) {
 					wsgi_req->async_placeholder = (SV *) *hitem;
 					return UWSGI_AGAIN;
 				}
@@ -161,7 +161,7 @@ int psgi_response(struct wsgi_request *wsgi_req, AV *response) {
                                 break;
 			}
 			SvREFCNT_dec(chunk);
-			if (uwsgi.async > 1) {
+			if (uwsgi.async > 0) {
 				wsgi_req->async_placeholder = (SV *) *hitem;
 				wsgi_req->async_force_again = 1;
 				return UWSGI_AGAIN;
diff --git a/plugins/pypy/pypy_setup.py b/plugins/pypy/pypy_setup.py
index 769c2386..67533ddc 100644
--- a/plugins/pypy/pypy_setup.py
+++ b/plugins/pypy/pypy_setup.py
@@ -980,7 +980,7 @@ def uwsgi_pypy_continulet_switch(wsgi_req):
     lib.uwsgi.wsgi_req = wsgi_req
     
 def uwsgi_pypy_setup_continulets():
-    if lib.uwsgi.async <= 1:
+    if lib.uwsgi.async < 1:
         raise Exception("pypy continulets require async mode !!!")
     lib.uwsgi.schedule_to_main = uwsgi_pypy_continulet_switch
     lib.uwsgi.schedule_to_req = uwsgi_pypy_continulet_schedule
diff --git a/plugins/python/pump_subhandler.c b/plugins/python/pump_subhandler.c
index 0e4f026f..42a84aef 100644
--- a/plugins/python/pump_subhandler.c
+++ b/plugins/python/pump_subhandler.c
@@ -255,7 +255,7 @@ int uwsgi_response_subhandler_pump(struct wsgi_request *wsgi_req) {
 				goto clear;
 			}
 
-			if (uwsgi.async > 1) {
+			if (uwsgi.async > 0) {
 				return UWSGI_AGAIN;
 			}
 
diff --git a/plugins/python/python_plugin.c b/plugins/python/python_plugin.c
index 9ab4c671..37f625af 100644
--- a/plugins/python/python_plugin.c
+++ b/plugins/python/python_plugin.c
@@ -361,7 +361,7 @@ void uwsgi_python_atexit() {
 		return;
 
 	// managing atexit in async mode is a real pain...skip it for now
-	if (uwsgi.async > 1)
+	if (uwsgi.async > 0)
 		return;
 realstuff:
 
@@ -1126,7 +1126,7 @@ void uwsgi_python_init_apps() {
 	}
 
 	// prepare for stack suspend/resume
-	if (uwsgi.async > 1) {
+	if (uwsgi.async > 0) {
 		up.current_recursion_depth = uwsgi_malloc(sizeof(int)*uwsgi.async);
         	up.current_frame = uwsgi_malloc(sizeof(struct _frame)*uwsgi.async);
 	}
diff --git a/plugins/python/pyutils.c b/plugins/python/pyutils.c
index f4b1ef3d..400c9f49 100644
--- a/plugins/python/pyutils.c
+++ b/plugins/python/pyutils.c
@@ -289,7 +289,7 @@ int uwsgi_python_call(struct wsgi_request *wsgi_req, PyObject *callable, PyObjec
 
 	if (wsgi_req->async_result) {
 		while ( manage_python_response(wsgi_req) != UWSGI_OK) {
-			if (uwsgi.async > 1) {
+			if (uwsgi.async > 0) {
 				return UWSGI_AGAIN;
 			}
 		}
diff --git a/plugins/python/raw.c b/plugins/python/raw.c
index c577bf1a..47f66d20 100644
--- a/plugins/python/raw.c
+++ b/plugins/python/raw.c
@@ -71,7 +71,7 @@ int uwsgi_request_python_raw(struct wsgi_request *wsgi_req) {
 			int ret = manage_raw_response(wsgi_req);
 			if (ret == UWSGI_AGAIN) {
 				wsgi_req->async_force_again = 1;
-				if (uwsgi.async > 1) {
+				if (uwsgi.async > 0) {
 					UWSGI_RELEASE_GIL return UWSGI_AGAIN;
 				}
 				continue;
diff --git a/plugins/python/web3_subhandler.c b/plugins/python/web3_subhandler.c
index 231a538d..48fe1623 100644
--- a/plugins/python/web3_subhandler.c
+++ b/plugins/python/web3_subhandler.c
@@ -164,7 +164,7 @@ int uwsgi_response_subhandler_web3(struct wsgi_request *wsgi_req) {
 			if (!wsgi_req->async_placeholder) {
 				goto clear;
 			}
-			if (uwsgi.async > 1) {
+			if (uwsgi.async > 0) {
 				return UWSGI_AGAIN;
 			}
 		}
diff --git a/plugins/python/wsgi_handlers.c b/plugins/python/wsgi_handlers.c
index 6cc091b3..94a398a1 100644
--- a/plugins/python/wsgi_handlers.c
+++ b/plugins/python/wsgi_handlers.c
@@ -405,7 +405,7 @@ int uwsgi_request_wsgi(struct wsgi_request *wsgi_req) {
 
 
 		while (wi->response_subhandler(wsgi_req) != UWSGI_OK) {
-			if (uwsgi.async > 1) {
+			if (uwsgi.async > 0) {
 				UWSGI_RELEASE_GIL
 				wsgi_req->async_force_again = 1;
 				return UWSGI_AGAIN;
diff --git a/plugins/python/wsgi_subhandler.c b/plugins/python/wsgi_subhandler.c
index 7eb57b08..3112ddb9 100644
--- a/plugins/python/wsgi_subhandler.c
+++ b/plugins/python/wsgi_subhandler.c
@@ -170,7 +170,7 @@ void *uwsgi_request_subhandler_wsgi(struct wsgi_request *wsgi_req, struct uwsgi_
 
 	PyDict_SetItemString(wsgi_req->async_environ, "wsgi.file_wrapper", wi->sendfile);
 
-	if (uwsgi.async > 1) {
+	if (uwsgi.async > 0) {
 		PyDict_SetItemString(wsgi_req->async_environ, "x-wsgiorg.fdevent.readable", wi->eventfd_read);
 		PyDict_SetItemString(wsgi_req->async_environ, "x-wsgiorg.fdevent.writable", wi->eventfd_write);
 		PyDict_SetItemString(wsgi_req->async_environ, "x-wsgiorg.fdevent.timeout", Py_None);
@@ -269,7 +269,7 @@ int uwsgi_response_subhandler_wsgi(struct wsgi_request *wsgi_req) {
 		if (!wsgi_req->async_placeholder) {
 			goto exception;
 		}
-		if (uwsgi.async > 1) {
+		if (uwsgi.async > 0) {
 			return UWSGI_AGAIN;
 		}
 	}
diff --git a/plugins/rados/rados.c b/plugins/rados/rados.c
index a12a15b8..86448bd5 100644
--- a/plugins/rados/rados.c
+++ b/plugins/rados/rados.c
@@ -90,7 +90,7 @@ static void uwsgi_rados_read_async_cb(rados_completion_t comp, void *data) {
 }
 
 static int uwsgi_rados_delete(struct wsgi_request *wsgi_req, rados_ioctx_t ctx, char *key, int timeout) {
-	if (uwsgi.async <= 1) {
+	if (uwsgi.async < 1) {
 		return rados_remove(ctx, key); 
 	}
 	struct uwsgi_rados_io *urio = &urados.urio[wsgi_req->async_id];
@@ -147,7 +147,7 @@ static int uwsgi_rados_put(struct wsgi_request *wsgi_req, rados_ioctx_t ctx, cha
                 ssize_t body_len = 0;
                 char *body =  uwsgi_request_body_read(wsgi_req, UMIN(remains, 32768) , &body_len);
                 if (!body || body == uwsgi.empty) goto error;
-		if (uwsgi.async <= 1) {
+		if (uwsgi.async < 1) {
 			if (rados_write(ctx, key, body, body_len, off) < 0) {
 				return -1;
 			}
@@ -368,7 +368,7 @@ static void uwsgi_rados_propfind(struct wsgi_request *wsgi_req, rados_ioctx_t ct
 	while(rados_objects_list_next(ctx_list, (const char **)&entry, NULL) == 0) {
 		uint64_t stat_size = 0;
 		time_t stat_mtime = 0;
-		if (uwsgi.async > 1) {
+		if (uwsgi.async > 0) {
         		if (uwsgi_rados_async_stat(urio, ctx, entry, &stat_size, &stat_mtime, timeout) < 0) goto end;
         	}
         	else {
@@ -513,7 +513,7 @@ static void uwsgi_rados_setup() {
 	}
 
 	// now initialize a pthread_mutex for each async core
-	if (uwsgi.async > 1) {
+	if (uwsgi.async > 0) {
 		int i;
 		urados.urio = uwsgi_calloc(sizeof(struct uwsgi_rados_io) * uwsgi.async);
 		for(i=0;i<uwsgi.async;i++) {
@@ -584,7 +584,7 @@ static int uwsgi_rados_request(struct wsgi_request *wsgi_req) {
 
 	struct uwsgi_rados_io *urio = &urados.urio[wsgi_req->async_id];
 
-	if (uwsgi.async > 1) {
+	if (uwsgi.async > 0) {
 	// no need to lock here (the rid protect us)
         	if (pipe(urio->fds)) {
                 	uwsgi_error("uwsgi_rados_read_async()/pipe()");
@@ -664,7 +664,7 @@ static int uwsgi_rados_request(struct wsgi_request *wsgi_req) {
                 goto end;
 	}
 
-	if (uwsgi.async > 1) {
+	if (uwsgi.async > 0) {
 		ret = uwsgi_rados_async_stat(urio, ctx, filename, &stat_size, &stat_mtime, timeout);	
 	}
 	else {
@@ -738,7 +738,7 @@ static int uwsgi_rados_request(struct wsgi_request *wsgi_req) {
 	// skip body on HEAD
 	if (uwsgi_strncmp(wsgi_req->method, wsgi_req->method_len, "HEAD", 4)) {
 		size_t remains = stat_size;
-		if (uwsgi.async > 1) {
+		if (uwsgi.async > 0) {
 			if (uwsgi_rados_read_async(wsgi_req, ctx, filename, remains, timeout)) goto end;
 		}
 		else {
@@ -747,7 +747,7 @@ static int uwsgi_rados_request(struct wsgi_request *wsgi_req) {
 	}
 
 end:
-	if (uwsgi.async > 1) {
+	if (uwsgi.async > 0) {
 		close(urio->fds[0]);
 		close(urio->fds[1]);
 	}
diff --git a/plugins/stackless/stackless.c b/plugins/stackless/stackless.c
index 94cfd673..0516c9f0 100644
--- a/plugins/stackless/stackless.c
+++ b/plugins/stackless/stackless.c
@@ -84,7 +84,7 @@ static void stackless_init_apps(void) {
 
 	if (!usl.enabled) return;
 
-	if (uwsgi.async <= 1) {
+	if (uwsgi.async < 1) {
                 uwsgi_log("the stackless suspend engine requires async mode\n");
                 exit(1);
         }
diff --git a/plugins/tornado/tornado.c b/plugins/tornado/tornado.c
index 9030506b..d7335104 100644
--- a/plugins/tornado/tornado.c
+++ b/plugins/tornado/tornado.c
@@ -342,7 +342,7 @@ static void tornado_loop() {
 
 	uwsgi.schedule_fix = uwsgi_tornado_schedule_fix;
 
-	if (uwsgi.async < 2) {
+	if (uwsgi.async < 1) {
 		uwsgi_log("the tornado loop engine requires async mode (--async <n>)\n");
 		exit(1);
 	}