diff -Naur old/ESP8266httpUpdate.cpp src/ESP8266httpUpdate.cpp
--- old/ESP8266httpUpdate.cpp	2018-03-08 05:19:25.000000000 +0100
+++ src/ESP8266httpUpdate.cpp	2018-07-14 10:43:44.581947667 +0200
@@ -249,10 +249,13 @@
 
                 WiFiClient * tcp = http.getStreamPtr();
 
-                WiFiUDP::stopAll();
-                WiFiClient::stopAllExcept(tcp);
+	        // https://github.com/esp8266/Arduino/issues/3359
+	        if(_severConnectionsOnUpdate) {
+		    WiFiUDP::stopAll();
+                    WiFiClient::stopAllExcept(tcp);
 
-                delay(100);
+                    delay(100);
+		}
 
                 int command;
 
diff -Naur old/ESP8266httpUpdate.h src/ESP8266httpUpdate.h
--- old/ESP8266httpUpdate.h	2018-03-08 05:19:25.000000000 +0100
+++ src/ESP8266httpUpdate.h	2018-07-14 10:38:51.035901594 +0200
@@ -71,6 +71,11 @@
         _rebootOnUpdate = reboot;
     }
 
+    void severConnectionsOnUpdate(bool sever)
+    {
+        _severConnectionsOnUpdate = sever;
+    }
+
     // This function is deprecated, use rebootOnUpdate and the next one instead
     t_httpUpdate_return update(const String& url, const String& currentVersion,
                                const String& httpsFingerprint, bool reboot) __attribute__((deprecated));
@@ -103,6 +108,7 @@
 
     int _lastError;
     bool _rebootOnUpdate = true;
+    bool _severConnectionsOnUpdate = true;
 };
 
 #if !defined(NO_GLOBAL_INSTANCES) && !defined(NO_GLOBAL_HTTPUPDATE)