diff --git a/README.md b/README.md
index f0a794d..3008140 100755
--- a/README.md
+++ b/README.md
@@ -61,6 +61,8 @@ The following environment variables are supported:
    be built and cached.  Note, `WORK_DIR` stores a complete copy of the target
    system for each build stage, amounting to tens of gigabytes in the case of
    Raspbian.
+   
+   **CAUTION**: If your working directory is on an NTFS partition you probably won't be able to build. Make sure this is a proper Linux filesystem.
 
  * `DEPLOY_DIR`  (Default: `"$BASE_DIR/deploy"`)