diff --git a/builder/main.py b/builder/main.py
index e7b8c00..1f01bf8 100644
--- a/builder/main.py
+++ b/builder/main.py
@@ -233,7 +233,7 @@ else:
     target_elf = env.BuildProgram()
     if set(["buildfs", "uploadfs", "uploadfsota"]) & set(COMMAND_LINE_TARGETS):
         target_firm = env.DataToBin(
-            join("$BUILD_DIR", "${ESP32_SPIFFS_IMAGE_NAME}"), "$PROJECTDATA_DIR")
+            join("$BUILD_DIR", "${ESP32_SPIFFS_IMAGE_NAME}"), "$PROJECT_DATA_DIR")
         env.NoCache(target_firm)
         AlwaysBuild(target_firm)
     else: