diff --git a/.github/CHANGELOG.md b/.github/CHANGELOG.md
index f162c996682..a3cccffd56e 100644
--- a/.github/CHANGELOG.md
+++ b/.github/CHANGELOG.md
@@ -141,6 +141,7 @@
 1. [FMS] Allow airport to be loaded as fixes in instrument procedures - @tracernz (Mike)
 1. [A380X/ND] Fix Terr text wrong position on terrain radar - @MrJigs7 (MrJigs.)
 1. [A380X/FMS] Vapp wind correction calculation fix - @Waveif (waveif)
+1. [A380X/MFD] Fixed FLT NBR not displaying as a mandatory input field - @jet2code (john.xyz)
 
 ## 0.12.0
 
diff --git a/fbw-a380x/src/systems/instruments/src/MFD/FMC/fmgc.ts b/fbw-a380x/src/systems/instruments/src/MFD/FMC/fmgc.ts
index ccc1a808639..3cab7f86913 100644
--- a/fbw-a380x/src/systems/instruments/src/MFD/FMC/fmgc.ts
+++ b/fbw-a380x/src/systems/instruments/src/MFD/FMC/fmgc.ts
@@ -61,7 +61,7 @@ export class FmgcData {
 
   public readonly cpnyFplnUplinkInProgress = Subject.create(false);
 
-  public readonly atcCallsign = Subject.create<string>('----------');
+  public readonly atcCallsign = Subject.create<string | null>(null);
 
   /** in degrees celsius. null if not set. */
   public readonly cruiseTemperaturePilotEntry = Subject.create<number | null>(null);
diff --git a/fbw-a380x/src/systems/instruments/src/MFD/MfdPageDirectory.tsx b/fbw-a380x/src/systems/instruments/src/MFD/MfdPageDirectory.tsx
index 8b84d3d9a92..fde3a77b18b 100644
--- a/fbw-a380x/src/systems/instruments/src/MFD/MfdPageDirectory.tsx
+++ b/fbw-a380x/src/systems/instruments/src/MFD/MfdPageDirectory.tsx
@@ -116,7 +116,7 @@ export function pageForUrl(
 export function headerForSystem(
   sys: string,
   mfd: DisplayInterface & MfdDisplayInterface,
-  atcCallsign: Subscribable<string>,
+  atcCallsign: Subscribable<string | null>,
   activeFmsSource: Subscribable<'FMS 1' | 'FMS 2' | 'FMS 1-C' | 'FMS 2-C'>,
   uiService: MfdUiService,
 ): VNode {
diff --git a/fbw-a380x/src/systems/instruments/src/MFD/pages/common/AbstractHeader.tsx b/fbw-a380x/src/systems/instruments/src/MFD/pages/common/AbstractHeader.tsx
index 36f9d5dcf9f..6d9a4ee711a 100644
--- a/fbw-a380x/src/systems/instruments/src/MFD/pages/common/AbstractHeader.tsx
+++ b/fbw-a380x/src/systems/instruments/src/MFD/pages/common/AbstractHeader.tsx
@@ -14,7 +14,7 @@ import { MfdUiService } from 'instruments/src/MFD/pages/common/MfdUiService';
 
 interface AbstractMfdHeaderProps {
   activeFmsSource: Subscribable<'FMS 1' | 'FMS 2' | 'FMS 1-C' | 'FMS 2-C'>;
-  callsign: Subscribable<string>;
+  callsign: Subscribable<string | null>;
   uiService: MfdUiService;
   mfd: DisplayInterface & MfdDisplayInterface;
 }
@@ -108,7 +108,9 @@ export abstract class AbstractHeader extends DisplayComponent<AbstractMfdHeaderP
           hEventConsumer={this.props.mfd.hEventConsumer}
           interactionMode={this.props.mfd.interactionMode}
         />
-        <span class="mfd-header-callsign">{this.props.callsign}</span>
+        <span class="mfd-header-callsign">
+          {this.props.callsign.map((cs) => (cs !== null ? this.props.callsign : '----------'))}
+        </span>
       </div>
     );
   }