diff --git a/ChangeLog.md b/ChangeLog.md
index cc95a44..aeccabe 100644
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -8,6 +8,9 @@ Note: This file only contains high level features or important fixes.
 
 * Major rewrite and bug fix pass through Structure Scan. Previous version had such bad problems that it can no longer be supported. Plans with Structure Scan will need to be recreated. New QGC will not load old Structure Scan plans.
 
+### 3.5.4 - Not yet released
+* Add .apj file selection support to custom firmware flash
+
 ### 3.5.3 - Stable
 * Change minimum RTK Survey-In limit to 0.01 meters
 * Change Windows driver detection logic
diff --git a/src/VehicleSetup/FirmwareUpgradeController.cc b/src/VehicleSetup/FirmwareUpgradeController.cc
index 3d189f4..5c27016 100644
--- a/src/VehicleSetup/FirmwareUpgradeController.cc
+++ b/src/VehicleSetup/FirmwareUpgradeController.cc
@@ -586,7 +586,7 @@ void FirmwareUpgradeController::_getFirmwareFile(FirmwareIdentifier firmwareId)
         _firmwareFilename = QGCQFileDialog::getOpenFileName(nullptr,                                                                // Parent to main window
                                                             tr("Select Firmware File"),                                             // Dialog Caption
                                                             QStandardPaths::writableLocation(QStandardPaths::DocumentsLocation),    // Initial directory
-                                                            tr("Firmware Files (*.px4 *.bin *.ihx)"));                              // File filter
+                                                            tr("Firmware Files (*.px4 *.apj *.bin *.ihx)"));                        // File filter
     } else {
         if (prgFirmware->contains(firmwareId)) {
             _firmwareFilename = prgFirmware->value(firmwareId);