diff --git a/bin/docker-install-build-deps.sh b/bin/docker-install-build-deps.sh
index 011ddba..9345201 100755
--- a/bin/docker-install-build-deps.sh
+++ b/bin/docker-install-build-deps.sh
@@ -56,13 +56,17 @@ if [ -n "$DEV_REF" ]; then
   git clone --depth 1 --branch "$DEV_REF" https://github.com/d3mlabs/dev.git /tmp/dev
   DEV_HOME=/tmp/dev
 else
-  echo ">>> Installing dev (latest release from the d3mlabs tap)"
-  brew install --quiet d3mlabs/d3mlabs/dev
+  echo ">>> Installing dev-core (latest release from the d3mlabs tap)"
+  # dev-core is the tool; the `dev` formula is the org DEPLOYMENT (org
+  # config + a dependency edge on dev-core). The image only runs
+  # install-build-deps.rb, which reads the project's dependencies.rb and
+  # needs no org identity, so install the tool directly.
+  brew install --quiet d3mlabs/d3mlabs/dev-core
   # The formula lays the tree out under libexec/dev with vendored gems in
-  # libexec (see homebrew-d3mlabs/Formula/dev.rb); mirror its wrapper env so
-  # the keg's scripts resolve their gems.
-  DEV_HOME="$(brew --prefix dev)/libexec/dev"
-  export GEM_HOME="$(brew --prefix dev)/libexec"
+  # libexec (see homebrew-d3mlabs/Formula/dev-core.rb); mirror its wrapper
+  # env so the keg's scripts resolve their gems.
+  DEV_HOME="$(brew --prefix dev-core)/libexec/dev"
+  export GEM_HOME="$(brew --prefix dev-core)/libexec"
   export GEM_PATH="$GEM_HOME"
 fi