diff --git a/platformio.ini b/platformio.ini
index 56f7f98..5f33e27 100644
--- a/platformio.ini
+++ b/platformio.ini
@@ -10,6 +10,15 @@
 ; Old envs preserved as historical snapshots — re-flashing units in the
 ; field stays a one-line `pio run -e <env> --target upload` command.
 
+; data_dir lives at project level (PlatformIO ignores it inside [env:…]
+; blocks — the silent ignore once led to a LittleFS upload that put every
+; file under /waveshare73-v1/ instead of /, blanking the panel to the
+; epd_fill yellow fallback). All current envs target the V1 panel; when
+; a second panel ships, swap this via an extra_scripts shim that picks
+; the dir from $PIOENV before uploadfs runs.
+[platformio]
+data_dir = data/waveshare73-v1
+
 ; ── Production firmware: Waveshare 7.3" Spectra-6 + ESP32 dev breakout ──
 [env:waveshare73-v1]
 platform = espressif32
@@ -19,7 +28,6 @@ upload_port = /dev/ttyUSB0
 monitor_port = /dev/ttyUSB0
 monitor_speed = 115200
 board_build.filesystem = littlefs
-data_dir = data/waveshare73-v1
 build_src_filter =
     +<main.cpp>
     +<panels/waveshare73/v1/>