diff --git a/doc/gitian-building.md b/doc/gitian-building.md
index 39fb5b6ba..58ebe072d 100644
--- a/doc/gitian-building.md
+++ b/doc/gitian-building.md
@@ -309,6 +309,12 @@ There will be a lot of warnings printed during build of the images. These can be
 
 **Note**: Repeat this step when you have upgraded to a newer version of Gitian.
 
+**Note**: if you get the error message *"bin/make-base-vm: mkfs.ext4: not found"* during this process you have to make the following change in file *"gitian-builder/bin/make-base-vm"* at line 117:
+```bash
+# mkfs.ext4 -F $OUT-lxc
+/sbin/mkfs.ext4 -F $OUT-lxc # (some Gitian environents do NOT find mkfs.ext4. Some do...)
+```
+
 Getting and building the inputs
 --------------------------------