diff --git a/bin/platformio-custom.py b/bin/platformio-custom.py
index 010ecd373..b75c66624 100644
--- a/bin/platformio-custom.py
+++ b/bin/platformio-custom.py
@@ -64,7 +64,7 @@ def manifest_gather(source, target, env):
     # Mapping of bin files to their target partition names
     # Maps the filename pattern to the partition name where it should be flashed
     partition_map = {
-        f"{progname}.bin": "app",              # primary application slot (app0 / OTA_0)
+        f"{progname}.bin": "app0",              # primary application slot (app0 / OTA_0)
         lfsbin: "spiffs",                        # filesystem image flashed to spiffs
     }