diff --git a/ChangeLog.md b/ChangeLog.md
index cc95a441774b76b53ff48cccf57feaa228a99422..aeccabeabebb535e35ca4c28d7f1c9ebddaad80e 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 3d189f463e2a66192f5eca85b611a8556fc5a22f..5c27016b4fb9c58434e2dcebf428e5c9a5bfeeb8 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);