diff --git a/.github/workflows/docker_latest.yml b/.github/workflows/docker_latest.yml
index 129d109e..7069ab50 100644
--- a/.github/workflows/docker_latest.yml
+++ b/.github/workflows/docker_latest.yml
@@ -70,6 +70,10 @@ jobs:
         with:
           ref: ${{ env.BRANCH }}
 
+      - name: Add a dummy ext/ directory
+        run:
+          mkdir ext && touch ext/dummy
+
       - name: Check out the ext/ directory
         if: matrix.image.name != 'grist-oss'
         run: buildtools/checkout-ext-directory.sh ${{ matrix.image.repo }}
diff --git a/ext/README.md b/ext/README.md
deleted file mode 100644
index 09f9848c..00000000
--- a/ext/README.md
+++ /dev/null
@@ -1,5 +0,0 @@
-`ext` is a directory that allows derivatives of Grist core to be created, without modifying any of the base files.
-
-Files placed in here should be new files, or replacing files in the `stubs` directory.
-
-When compiling, Typescript resolves files in `ext` before files in `stubs`, using the `ext` file instead (if it exists).