diff --git a/autorecon/main.py b/autorecon/main.py
index c5abcb4..5de2cdf 100644
--- a/autorecon/main.py
+++ b/autorecon/main.py
@@ -509,7 +509,7 @@ async def scan_target(target):
 
 	target.reportdir = reportdir
 
-	pending = []
+	pending = set()
 
 	heartbeat = asyncio.create_task(start_heartbeat(target, period=config['heartbeat']))
 
@@ -532,7 +532,7 @@ async def scan_target(target):
 				services.append(service)
 
 		if services:
-			pending.append(asyncio.create_task(asyncio.sleep(0)))
+			pending.add(asyncio.create_task(asyncio.sleep(0)))
 		else:
 			error('No services were defined. Please check your service syntax: [tcp|udp]/<port>/<service-name>/[secure|insecure]')
 			heartbeat.cancel()
@@ -568,7 +568,7 @@ async def scan_target(target):
 
 			if matching_tags and not excluded_tags:
 				target.scans['ports'][plugin.slug] = {'plugin':plugin, 'commands':[]}
-				pending.append(asyncio.create_task(port_scan(plugin, target)))
+				pending.add(asyncio.create_task(port_scan(plugin, target)))
 
 	async with autorecon.lock:
 		autorecon.scanning_targets.append(target)
@@ -1549,10 +1549,10 @@ async def run():
 	if not config['disable_keyboard_control']:
 		terminal_settings = termios.tcgetattr(sys.stdin.fileno())
 
-	pending = []
+	pending = set()
 	i = 0
 	while autorecon.pending_targets:
-		pending.append(asyncio.create_task(scan_target(autorecon.pending_targets.pop(0))))
+		pending.add(asyncio.create_task(scan_target(autorecon.pending_targets.pop(0))))
 		i+=1
 		if i >= num_initial_targets:
 			break