diff --git a/tasmota/CHANGELOG.md b/tasmota/CHANGELOG.md
index edf6108e0..b5036467c 100644
--- a/tasmota/CHANGELOG.md
+++ b/tasmota/CHANGELOG.md
@@ -3,6 +3,7 @@
 ### 8.1.0.5 20200126
 
 - Change wifi connectivity stability (#7602)
+- Add ``SetOption84 1`` sends AWS IoT device shadow updates (alternative to retained)
 
 ### 8.1.0.4 20200116
 
diff --git a/tasmota/settings.h b/tasmota/settings.h
index dba74eb7d..cef401a94 100644
--- a/tasmota/settings.h
+++ b/tasmota/settings.h
@@ -102,8 +102,8 @@ typedef union {                            // Restricted by MISRA-C Rule 18.4 bu
   uint32_t data;                           // Allow bit manipulation using SetOption
   struct {                                 // SetOption82 .. SetOption113
     uint32_t alexa_ct_range : 1;           // bit 0 (v8.1.0.2)   - SetOption82 - Reduced CT range for Alexa
-    uint32_t zigbee_use_names : 1;         // bit 1 (V8.1.0.4)   - SetOption83 - Use FriendlyNames instead of ShortAddresses when possible
-    uint32_t spare02 : 1;
+    uint32_t zigbee_use_names : 1;         // bit 1 (v8.1.0.4)   - SetOption83 - Use FriendlyNames instead of ShortAddresses when possible
+    uint32_t awsiot_shadow : 1;            // bit 2 (v8.1.0.5)   - SetOption84 - (AWS IoT) publish MQTT state to a device shadow
     uint32_t spare03 : 1;
     uint32_t spare04 : 1;
     uint32_t spare05 : 1;
diff --git a/tasmota/xdrv_02_mqtt.ino b/tasmota/xdrv_02_mqtt.ino
index 05072d5c7..55b63c4de 100644
--- a/tasmota/xdrv_02_mqtt.ino
+++ b/tasmota/xdrv_02_mqtt.ino
@@ -362,7 +362,7 @@ void MqttPublishPrefixTopic_P(uint32_t prefix, const char* subtopic, bool retain
  * prefix 5 = stat using subtopic or RESULT
  * prefix 6 = tele using subtopic or RESULT
  */
-  char romram[33];
+  char romram[64];
   char stopic[TOPSZ];
 
   snprintf_P(romram, sizeof(romram), ((prefix > 3) && !Settings.flag.mqtt_response) ? S_RSLT_RESULT : subtopic);  // SetOption4 - Switch between MQTT RESULT or COMMAND
@@ -372,6 +372,36 @@ void MqttPublishPrefixTopic_P(uint32_t prefix, const char* subtopic, bool retain
   prefix &= 3;
   GetTopic_P(stopic, prefix, mqtt_topic, romram);
   MqttPublish(stopic, retained);
+
+#ifdef USE_MQTT_AWS_IOT
+  if ((prefix > 0) && (Settings.flag4.awsiot_shadow)) {    // placeholder for SetOptionXX
+    // compute the target topic
+    char *topic = SettingsText(SET_MQTT_TOPIC);
+    char topic2[strlen(topic)+1];       // save buffer onto stack
+    strcpy(topic2, topic);
+    // replace any '/' with '_'
+    char *s = topic2;
+    while (*s) {
+      if ('/' == *s) {
+        *s = '_';
+      }
+      s++;
+    }
+    // update topic is "$aws/things/<topic>/shadow/update"
+    snprintf_P(romram, sizeof(romram), PSTR("$aws/things/%s/shadow/update"), topic2);
+    
+    // copy buffer
+    char *mqtt_save = (char*) malloc(strlen(mqtt_data)+1);
+    if (!mqtt_save) { return; }    // abort
+    strcpy(mqtt_save, mqtt_data);
+    snprintf_P(mqtt_data, sizeof(mqtt_data), PSTR("{\"state\":{\"reported\":%s}}"), mqtt_save);
+    free(mqtt_save);
+
+    bool result = MqttClient.publish(romram, mqtt_data, false);
+    AddLog_P2(LOG_LEVEL_INFO, PSTR(D_LOG_MQTT "Updated shadow: %s"), romram);
+    yield();  // #3313
+  }
+#endif // USE_MQTT_AWS_IOT
 }
 
 void MqttPublishPrefixTopic_P(uint32_t prefix, const char* subtopic)