diff --git a/resources/settings/properties.xml b/resources/settings/properties.xml
index d588b4d..204ed33 100644
--- a/resources/settings/properties.xml
+++ b/resources/settings/properties.xml
@@ -94,6 +94,20 @@
   -->
   <property id="battery_level_refresh_rate" type="number">15</property>
 
+  <!--
+    A user specified HTTP header key to be used in all HTTP requests.
+    This is useful for some Home Assistant installations that require a
+    custom HTTP header.
+  -->
+  <property id="user_http_header_key" type="string"></property>
+
+  <!--
+    A user specified HTTP header value to be used in all HTTP requests.
+    This is useful for some Home Assistant installations that require a
+    custom HTTP header.
+  -->
+  <property id="user_http_header_value" type="string"></property>
+
   <!--
     The webhook ID is the last part of the webhook URL. It is secret and
     should not be shared. It will not be set in settings but will be
diff --git a/resources/settings/settings.xml b/resources/settings/settings.xml
index 6c2cc87..f9a00ae 100644
--- a/resources/settings/settings.xml
+++ b/resources/settings/settings.xml
@@ -119,6 +119,22 @@
     <settingConfig type="numeric" min="5" />
   </setting>
 
+  <group id="userHttpHeader" title="@Strings.SettingsUserHttpHeader" description="@Strings.SettingsUserHttpHeaderDescription">
+    <setting
+      propertyKey="@Properties.user_http_header_key"
+      title="@Strings.SettingsUserHttpHeaderKey"
+    >
+      <settingConfig type="alphaNumeric" />
+    </setting>
+
+    <setting
+      propertyKey="@Properties.user_http_header_value"
+      title="@Strings.SettingsUserHttpHeaderValue"
+    >
+      <settingConfig type="alphaNumeric" />
+    </setting>
+  </group>
+
   <setting
     propertyKey="@Properties.webhook_id"
     title="@Strings.WebhookId"
diff --git a/resources/strings/strings.xml b/resources/strings/strings.xml
index c242e9a..2a34ae8 100644
--- a/resources/strings/strings.xml
+++ b/resources/strings/strings.xml
@@ -57,6 +57,9 @@
   <string id="SettingsConfigUrl">URL for menu configuration (JSON).</string>
   <string id="SettingsCacheConfig">Should the application cache the menu configuration?</string>
   <string id="SettingsClearCache">Should the application clear the existing cache next time it is started?</string>
+  <string id="WifiLteExecution">Wi-Fi/LTE execution mode.</string>
+  <string id="WifiLteExecutionEnable">Enable executing commands over Wi-Fi/LTE.</string>
+  <string id="WifiLteExecutionDescription">Allows the app to start without phone connection (when menu is cached), and prompt to execute command over Wi-Fi/LTE.</string>
   <string id="SettingsVibration">Should the application provide feedback via vibrations?</string>
   <string id="SettingsAppTimeout">Timeout in seconds. Exit the application after this period of inactivity to save the device battery.</string>
   <string id="SettingsPollDelay">Additional poll delay (in seconds). Adds a delay between the status update of all menu items.</string>
@@ -69,8 +72,9 @@
   <string id="SettingsWidgetStart">(Widget only) Automatically start the application from the widget without waiting for a tap.</string>
   <string id="SettingsEnableBatteryLevel">Enable the background service to send the device battery level, location and (if supported) activity data to Home Assistant.</string>
   <string id="SettingsBatteryLevelRefreshRate">The refresh rate (in minutes) at which the background service should repeat sending data.</string>
+  <string id="SettingsUserHttpHeader">User supplied HTTP header</string>
+  <string id="SettingsUserHttpHeaderDescription">Some Home Assistant installations require the specification of a custom HTTP header in order to function.</string>
+  <string id="SettingsUserHttpHeaderKey">User supplied HTTP header key.</string>
+  <string id="SettingsUserHttpHeaderValue">User supplied HTTP header value.</string>
   <string id="WebhookId">(Read only) The Webhook ID created by the device for background service updates. You might require this for debugging.</string>
-  <string id="WifiLteExecution">Wi-Fi/LTE execution mode.</string>
-  <string id="WifiLteExecutionEnable">Enable executing commands over Wi-Fi/LTE.</string>
-  <string id="WifiLteExecutionDescription">Allows the app to start without phone connection (when menu is cached), and prompt to execute command over Wi-Fi/LTE.</string>
 </strings>
diff --git a/source/BackgroundServiceDelegate.mc b/source/BackgroundServiceDelegate.mc
index 71ea4c5..feaa4d4 100644
--- a/source/BackgroundServiceDelegate.mc
+++ b/source/BackgroundServiceDelegate.mc
@@ -158,9 +158,9 @@ class BackgroundServiceDelegate extends System.ServiceDelegate {
                 },
                 {
                     :method       => Communications.HTTP_REQUEST_METHOD_POST,
-                    :headers      => {
+                    :headers      => Settings.augmentHttpHeaders({
                         "Content-Type" => Communications.REQUEST_CONTENT_TYPE_JSON
-                    },
+                    }),
                     :responseType => Communications.HTTP_RESPONSE_CONTENT_TYPE_JSON
                 },
                 method(:onReturnDoUpdate)
@@ -244,9 +244,9 @@ class BackgroundServiceDelegate extends System.ServiceDelegate {
             },
             {
                 :method       => Communications.HTTP_REQUEST_METHOD_POST,
-                :headers      => {
+                :headers      => Settings.augmentHttpHeaders({
                     "Content-Type" => Communications.REQUEST_CONTENT_TYPE_JSON
-                },
+                }),
                 :responseType => Communications.HTTP_RESPONSE_CONTENT_TYPE_JSON
             },
             method(:onReturnDoUpdate)
diff --git a/source/HomeAssistantApp.mc b/source/HomeAssistantApp.mc
index 985241b..9075c7b 100644
--- a/source/HomeAssistantApp.mc
+++ b/source/HomeAssistantApp.mc
@@ -287,7 +287,8 @@ class HomeAssistantApp extends Application.AppBase {
                         null,
                         {
                             :method       => Communications.HTTP_REQUEST_METHOD_GET,
-                            :responseType => Communications.HTTP_RESPONSE_CONTENT_TYPE_JSON
+                            :responseType => Communications.HTTP_RESPONSE_CONTENT_TYPE_JSON,
+                            :headers      => Settings.augmentHttpHeaders({})
                         },
                         method(:onReturnFetchMenuConfig)
                     );
@@ -501,9 +502,9 @@ class HomeAssistantApp extends Application.AppBase {
                 },
                 {
                     :method       => Communications.HTTP_REQUEST_METHOD_POST,
-                    :headers      => {
+                    :headers      => Settings.augmentHttpHeaders({
                         "Content-Type" => Communications.REQUEST_CONTENT_TYPE_JSON
-                    },
+                    }),
                     :responseType => Communications.HTTP_RESPONSE_CONTENT_TYPE_JSON
                 },
                 method(:onReturnUpdateMenuItems)
@@ -619,9 +620,9 @@ class HomeAssistantApp extends Application.AppBase {
                     null,
                     {
                         :method       => Communications.HTTP_REQUEST_METHOD_GET,
-                        :headers      => {
+                        :headers      => Settings.augmentHttpHeaders({
                             "Authorization" => "Bearer " + Settings.getApiKey()
-                        },
+                        }),
                         :responseType => Communications.HTTP_RESPONSE_CONTENT_TYPE_JSON
                     },
                     method(:onReturnFetchApiStatus)
@@ -714,9 +715,9 @@ class HomeAssistantApp extends Application.AppBase {
                 },
                 {
                     :method       => Communications.HTTP_REQUEST_METHOD_POST,
-                    :headers      => {
+                    :headers      => Settings.augmentHttpHeaders({
                         "Content-Type" => Communications.REQUEST_CONTENT_TYPE_JSON
-                    },
+                    }),
                     :responseType => Communications.HTTP_RESPONSE_CONTENT_TYPE_JSON
                 },
                 method(:onReturnFetchGlanceContent)
diff --git a/source/HomeAssistantService.mc b/source/HomeAssistantService.mc
index 6e14882..459c189 100644
--- a/source/HomeAssistantService.mc
+++ b/source/HomeAssistantService.mc
@@ -168,10 +168,10 @@ class HomeAssistantService {
                 data, // Includes {"entity_id": xxxx}
                 {
                     :method       => Communications.HTTP_REQUEST_METHOD_POST,
-                    :headers      => {
+                    :headers      => Settings.augmentHttpHeaders({
                         "Content-Type"  => Communications.REQUEST_CONTENT_TYPE_JSON,
                         "Authorization" => "Bearer " + Settings.getApiKey()
-                    },
+                    }),
                     :responseType => Communications.HTTP_RESPONSE_CONTENT_TYPE_JSON,
                     :context      => {
                         :entity_id => entity_id,
diff --git a/source/HomeAssistantSyncDelegate.mc b/source/HomeAssistantSyncDelegate.mc
index 81ef1d9..31210aa 100644
--- a/source/HomeAssistantSyncDelegate.mc
+++ b/source/HomeAssistantSyncDelegate.mc
@@ -81,10 +81,10 @@ class HomeAssistantSyncDelegate extends Communications.SyncDelegate {
             data, // May include {"entity_id": xxxx} for service calls
             {
                 :method  => Communications.HTTP_REQUEST_METHOD_POST,
-                :headers => {
+                :headers => Settings.augmentHttpHeaders({
                     "Content-Type"  => Communications.REQUEST_CONTENT_TYPE_JSON,
                     "Authorization" => "Bearer " + Settings.getApiKey()
-                },
+                }),
                 :responseType => Communications.HTTP_RESPONSE_CONTENT_TYPE_JSON,
             },
             method(:haCallback)
diff --git a/source/HomeAssistantToggleMenuItem.mc b/source/HomeAssistantToggleMenuItem.mc
index a8efdb5..96c04d5 100644
--- a/source/HomeAssistantToggleMenuItem.mc
+++ b/source/HomeAssistantToggleMenuItem.mc
@@ -268,10 +268,10 @@ class HomeAssistantToggleMenuItem extends WatchUi.ToggleMenuItem {
                 mData,
                 {
                     :method       => Communications.HTTP_REQUEST_METHOD_POST,
-                    :headers      => {
+                    :headers      => Settings.augmentHttpHeaders({
                         "Content-Type"  => Communications.REQUEST_CONTENT_TYPE_JSON,
                         "Authorization" => "Bearer " + Settings.getApiKey()
-                    },
+                    }),
                     :responseType => Communications.HTTP_RESPONSE_CONTENT_TYPE_JSON
                 },
                 method(:onReturnSetState)
diff --git a/source/Settings.mc b/source/Settings.mc
index c304ee3..79a67e2 100644
--- a/source/Settings.mc
+++ b/source/Settings.mc
@@ -47,6 +47,10 @@ class Settings {
     private static var mIsSensorsLevelEnabled as Lang.Boolean = false;
     //! minutes
     private static var mBatteryRefreshRate    as Lang.Number  = 15;
+    //! Additional user configurable HTTP header key
+    private static var mUserHeaderKey         as Lang.String  = "";
+    //! Additional user configurable HTTP header value
+    private static var mUserHeaderValue       as Lang.String  = "";
     private static var mIsApp                 as Lang.Boolean = false;
     private static var mHasService            as Lang.Boolean = false;
     //! Must keep the object so it doesn't get garbage collected.
@@ -71,6 +75,8 @@ class Settings {
         mMenuAlignment         = Properties.getValue("menu_alignment");
         mIsSensorsLevelEnabled = Properties.getValue("enable_battery_level");
         mBatteryRefreshRate    = Properties.getValue("battery_level_refresh_rate");
+        mUserHeaderKey         = Properties.getValue("user_http_header_key");
+        mUserHeaderValue       = Properties.getValue("user_http_header_value");
     }
 
     //! A webhook is required for non-privileged API calls.
@@ -284,4 +290,17 @@ class Settings {
         }
     }
 
+    //! Augment the HTTP header options passed in with the user configurable HTTP header key and value.
+    //!
+    //! @param options The HTTP header options to augment.
+    //!
+    //! @return The augmented HTTP header options.
+    //
+    static function augmentHttpHeaders(options as Lang.Dictionary) {
+        if (mUserHeaderKey != null && mUserHeaderKey != "" && mUserHeaderValue != null && mUserHeaderValue != "") {
+            options[mUserHeaderKey] = mUserHeaderValue;
+        }
+        return options;
+    }
+
 }
diff --git a/source/WebhookManager.mc b/source/WebhookManager.mc
index b6a9a19..6d43835 100644
--- a/source/WebhookManager.mc
+++ b/source/WebhookManager.mc
@@ -113,10 +113,10 @@ class WebhookManager {
             },
             {
                 :method       => Communications.HTTP_REQUEST_METHOD_POST,
-                :headers      => {
+                :headers      => Settings.augmentHttpHeaders({
                     "Content-Type"  => Communications.REQUEST_CONTENT_TYPE_JSON,
                     "Authorization" => "Bearer " + Settings.getApiKey()
-                },
+                }),
                 :responseType => Communications.HTTP_RESPONSE_CONTENT_TYPE_JSON
             },
             method(:onReturnRequestWebhookId)
@@ -230,9 +230,9 @@ class WebhookManager {
             },
             {
                 :method       => Communications.HTTP_REQUEST_METHOD_POST,
-                :headers      => {
+                :headers      => Settings.augmentHttpHeaders({
                     "Content-Type" => Communications.REQUEST_CONTENT_TYPE_JSON
-                },
+                }),
                 :responseType => Communications.HTTP_RESPONSE_CONTENT_TYPE_JSON,
                 :context      => sensors.slice(1, null)
             },