diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 9a9f725780da0..21db307dabc1e 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -446,19 +446,41 @@ check-polkadot-companion-status:
   script:
     - ./.maintain/gitlab/check_polkadot_companion_status.sh
 
-check-polkadot-companion-build:
-  stage:                           build
+.check-companion-build:            &check-companion-build
+  stage:                           test
   <<:                              *docker-env
   <<:                              *test-refs-no-trigger
-  needs:
-    - job:                         test-linux-stable-int
-      artifacts:                   false
   script:
-    - ./.maintain/gitlab/check_polkadot_companion_build.sh
+    - ./.maintain/gitlab/check_companion_build.sh "$COMPANION_ORG" "$COMPANION_REPO" "$COMPANION_BUILD" "$COMPANION_DEPENDENCY"
   after_script:
-    - cd polkadot && git rev-parse --abbrev-ref HEAD
+    - cd "$COMPANION_REPO" && git rev-parse --abbrev-ref HEAD
   allow_failure:                   true
 
+check-polkadot-companion-build:
+  <<: *check-companion-build
+  variables:
+    COMPANION_ORG: paritytech
+    COMPANION_REPO: polkadot
+    COMPANION_DEPENDENCY: paritytech/grandpa-bridge-gadget
+  allow_failure: true
+
+check-cumulus-companion-build:
+  <<: *check-companion-build
+  variables:
+    COMPANION_ORG: paritytech
+    COMPANION_REPO: cumulus
+    COMPANION_BUILD: "cargo check --all-targets --workspace"
+    COMPANION_DEPENDENCY: paritytech/polkadot
+  allow_failure: true
+
+check-beefy-companion-build:
+  <<: *check-companion-build
+  variables:
+    COMPANION_ORG: paritytech
+    COMPANION_REPO: grandpa-bridge-gadget
+    COMPANION_BUILD: "cargo check --all-targets --workspace"
+  allow_failure: true
+
 test-browser-node:
   stage:                           build
   <<:                              *docker-env
diff --git a/.maintain/common/lib.sh b/.maintain/common/lib.sh
index ce6c566d799ab..e0104f5da9976 100755
--- a/.maintain/common/lib.sh
+++ b/.maintain/common/lib.sh
@@ -2,6 +2,18 @@
 
 api_base="https://api.github.com/repos"
 
+
+set_github_token(){
+  # These will exist if the function is called in Gitlab.
+  # If the function's called in Github, we should have GITHUB_ACCESS_TOKEN set
+  # already.
+  if [ -n "$GITHUB_RELEASE_TOKEN" ]; then
+    GITHUB_TOKEN="$GITHUB_RELEASE_TOKEN"
+  elif [ -n "$GITHUB_PR_TOKEN" ]; then
+    GITHUB_TOKEN="$GITHUB_PR_TOKEN"
+  fi
+}
+
 # Function to take 2 git tags/commits and get any lines from commit messages
 # that contain something that looks like a PR reference: e.g., (#1234)
 sanitised_git_logs(){
@@ -66,15 +78,7 @@ has_label(){
   repo="$1"
   pr_id="$2"
   label="$3"
-
-  # These will exist if the function is called in Gitlab.
-  # If the function's called in Github, we should have GITHUB_ACCESS_TOKEN set
-  # already.
-  if [ -n "$GITHUB_RELEASE_TOKEN" ]; then
-    GITHUB_TOKEN="$GITHUB_RELEASE_TOKEN"
-  elif [ -n "$GITHUB_PR_TOKEN" ]; then
-    GITHUB_TOKEN="$GITHUB_PR_TOKEN"
-  fi
+  set_github_token
 
   out=$(curl -H "Authorization: token $GITHUB_TOKEN" -s "$api_base/$repo/pulls/$pr_id")
   [ -n "$(echo "$out" | tr -d '\r\n' | jq ".labels | .[] | select(.name==\"$label\")")" ]
@@ -115,3 +119,23 @@ has_runtime_changes() {
     return 1
   fi
 }
+
+# Given an origin repo & PR,and a repository, will check if the given PR has a
+# companion PR in the target repo
+get_companion() {
+  origin_repo="$1"
+  pr_num="$2"
+  companion_repo="$3"
+  set_github_token
+  github_header="Authorization: token ${GITHUB_TOKEN}"
+  # get the last reference to a pr in the target repo
+  pr_body=$(
+    curl -sSL -H "${github_header}" "${api_base}/$origin_repo/pulls/$pr_num" | \
+      jq -r '.body'
+  )
+
+  echo "${pr_body}" | sed -n -r \
+      -e "s;^.*[Cc]ompanion.*$companion_repo#([0-9]+).*$;\1;p" \
+      -e "s;^.*[Cc]ompanion.*https://github.com/$companion_repo/pull/([0-9]+).*$;\1;p" \
+    | tail -n 1
+}
diff --git a/.maintain/gitlab/check_companion_build.sh b/.maintain/gitlab/check_companion_build.sh
new file mode 100755
index 0000000000000..2d6a2f896e198
--- /dev/null
+++ b/.maintain/gitlab/check_companion_build.sh
@@ -0,0 +1,123 @@
+#!/usr/bin/env bash
+#
+# check if a pr is compatible with companion pr or master if not available
+#
+# to override one that was just mentioned mark companion pr in the body of the
+# pr like
+#
+# $REPO companion: $ORGANISATION/$REPO#567
+#
+# $ORGANISATION and $REPO are set using $1 and $2. You can also specify a custom
+# build command with $3
+# Every argument after $3 is for specifying *additional* dependencies this
+# project has that depend on substrate, which might also have companion PRs.
+
+# Example: Cumulus relies on both substrate and polkadot. If this substrate PR
+# requires a companion build on polkadot, when we are testing that cumulus builds
+# with this commit of substrate, we *also* need to clone & patch polkadot, and tell
+# cumulus to use this cloned+patched version, else the build is guaranteed to fail
+# (since it doesn't have the changes to polkadot that were required in the polkadot
+# companion PR)
+
+# So invoke this script like (arguments in [] indicate optional arguments)
+# ./check_companion_build.sh paritytech cumulus ['cargo test --release'] [paritytech/polkadot]
+
+set -e
+
+# Include the common functions library
+#shellcheck source=../common/lib.sh
+. "$(dirname "${0}")/../common/lib.sh"
+
+ORGANISATION=$1
+REPO=$2
+BUILDSTRING=${3:-cargo test --workspace --release}
+DEPS=("${@:4}")
+SUBSTRATE_DIR="$(pwd)"
+
+boldprint () { printf "|\n| \033[1m%s\033[0m\n|\n" "${@}"; }
+boldcat () { printf "|\n"; while read -r l; do printf "| \033[1m%s\033[0m\n" "${l}"; done; printf "|\n" ; }
+
+boldcat <<-EOT
+
+
+check_${REPO}_companion_build
+==============================
+
+this job checks if there is a string in the description of the pr like
+
+$REPO companion: $ORGANISATION/$REPO#567
+
+
+it will then run cargo check from this ${REPO}'s branch with substrate code
+from this pull request. otherwise, it will uses master instead
+
+
+EOT
+
+# Set the user name and email to make merging work
+git config --global user.name 'CI system'
+git config --global user.email '<>'
+
+# Merge master into our branch before building to make sure we don't miss
+# any commits that are required.
+git fetch --depth 100 origin
+git merge origin/master
+
+# Clone the current master branch into a local directory
+# NOTE: we need to pull enough commits to be able to find a common
+# ancestor for successfully performing merges below.
+git clone --depth 20 "https://github.com/${ORGANISATION}/${REPO}.git"
+
+cd "$REPO"
+
+# either it's a pull request then check for a companion otherwise use
+# master
+# shellcheck disable=SC2003
+if expr match "${CI_COMMIT_REF_NAME}" '^[0-9]\+$' >/dev/null
+then
+  boldprint "this is pull request no ${CI_COMMIT_REF_NAME}"
+  pr_companion="$(get_companion "paritytech/substrate" "$CI_COMMIT_REF_NAME" "$ORGANISATION/$REPO")"
+  if [ "$pr_companion" ]
+  then
+    boldprint "companion pr specified/detected: #${pr_companion}"
+    git fetch origin "refs/pull/${pr_companion}/head:pr/${pr_companion}"
+    git checkout "pr/${pr_companion}"
+    git merge origin/master
+  else
+    boldprint "no companion branch found - building ${REPO}:master"
+  fi
+
+  # If this repo has any additional dependencies, we should check whether they
+  # are mentioned as companions as well. If they are, we patch this repo to
+  # use that companion build as well. See example at top of this script
+  # Note: Will only work with repos supported by diener
+  declare -A diener_commands
+  diener_commands=()
+  diener_commands["paritytech/polkadot"]='--polkadot'
+  diener_commands["paritytech/substrate"]='--substrate'
+  diener_commands["paritytech/grandpa-bridge-gadget"]='--beefy'
+
+  for dep in "${DEPS[@]}"; do
+    dep_companion="$(get_companion "paritytech/substrate" "$CI_COMMIT_REF_NAME" "$dep")"
+    if [ "$dep_companion" ]; then
+      echo "Companion PR found for $dep, need to patch $REPO to use that"
+      git clone --depth 20 "https://github.com/$dep.git" "$dep"
+      git -C "$dep" fetch origin "refs/pull/${dep_companion}/head:pr/${dep_companion}"
+      git -C "$dep" checkout "pr/${dep_companion}"
+      git -C "$dep" merge origin/master
+      # Tell this dependency to use the version of substrate in this PR
+      diener patch --crates-to-patch "$SUBSTRATE_DIR" --substrate --path "$dep/Cargo.toml"
+      # then we tell this repository to point at our locally cloned dependency
+      diener patch --crates-to-patch "$dep" "${diener_commands[$dep]}" --path "Cargo.toml"
+    fi
+
+  done
+
+else
+  boldprint "this is not a pull request - building ${REPO}:master"
+fi
+
+# Test pr or master branch with this Substrate commit.
+diener patch --crates-to-patch ".." --substrate --path "Cargo.toml"
+
+eval "$BUILDSTRING"
diff --git a/.maintain/gitlab/check_polkadot_companion_build.sh b/.maintain/gitlab/check_polkadot_companion_build.sh
deleted file mode 100755
index 72bfaf7151522..0000000000000
--- a/.maintain/gitlab/check_polkadot_companion_build.sh
+++ /dev/null
@@ -1,99 +0,0 @@
-#!/usr/bin/env sh
-#
-# check if a pr is compatible with polkadot companion pr or master if not
-# available
-#
-# to override one that was just mentioned mark companion pr in the body of the
-# polkadot pr like
-#
-# polkadot companion: paritytech/polkadot#567
-#
-
-set -e
-
-github_api_substrate_pull_url="https://api.github.com/repos/paritytech/substrate/pulls"
-# use github api v3 in order to access the data without authentication
-github_header="Authorization: token ${GITHUB_PR_TOKEN}"
-
-boldprint () { printf "|\n| \033[1m${@}\033[0m\n|\n" ; }
-boldcat () { printf "|\n"; while read l; do printf "| \033[1m${l}\033[0m\n"; done; printf "|\n" ; }
-
-
-
-boldcat <<-EOT
-
-
-check_polkadot_companion_build
-==============================
-
-this job checks if there is a string in the description of the pr like
-
-polkadot companion: paritytech/polkadot#567
-
-
-it will then run cargo check from this polkadot's branch with substrate code
-from this pull request. otherwise, it will uses master instead
-
-
-EOT
-
-# Set the user name and email to make merging work
-git config --global user.name 'CI system'
-git config --global user.email '<>'
-
-# Merge master into our branch before building Polkadot to make sure we don't miss
-# any commits that are required by Polkadot.
-git fetch --depth 100 origin
-git merge origin/master
-
-# Clone the current Polkadot master branch into ./polkadot.
-# NOTE: we need to pull enough commits to be able to find a common
-# ancestor for successfully performing merges below.
-git clone --depth 20 https://github.com/paritytech/polkadot.git
-
-cd polkadot
-
-# either it's a pull request then check for a companion otherwise use
-# polkadot:master
-if expr match "${CI_COMMIT_REF_NAME}" '^[0-9]\+$' >/dev/null
-then
-  boldprint "this is pull request no ${CI_COMMIT_REF_NAME}"
-
-  pr_data_file="$(mktemp)"
-  # get the last reference to a pr in polkadot
-  curl -sSL -H "${github_header}" -o "${pr_data_file}" \
-    "${github_api_substrate_pull_url}/${CI_COMMIT_REF_NAME}"
-
-  pr_body="$(sed -n -r 's/^[[:space:]]+"body": (".*")[^"]+$/\1/p' "${pr_data_file}")"
-
-  pr_companion="$(echo "${pr_body}" | sed -n -r \
-      -e 's;^.*[Cc]ompanion.*paritytech/polkadot#([0-9]+).*$;\1;p' \
-      -e 's;^.*[Cc]ompanion.*https://github.com/paritytech/polkadot/pull/([0-9]+).*$;\1;p' \
-    | tail -n 1)"
-
-  if [ "${pr_companion}" ]
-  then
-    boldprint "companion pr specified/detected: #${pr_companion}"
-    git fetch origin refs/pull/${pr_companion}/head:pr/${pr_companion}
-    git checkout pr/${pr_companion}
-    git merge origin/master
-  else
-    boldprint "no companion branch found - building polkadot:master"
-  fi
-  rm -f "${pr_data_file}"
-else
-  boldprint "this is not a pull request - building polkadot:master"
-fi
-
-# Patch all Substrate crates in Polkadot
-diener patch --crates-to-patch ../ --substrate --path Cargo.toml
-
-# We need to update specifically our patched Substrate crates so that other
-# crates that depend on them (e.g. Polkadot, BEEFY) use this unified version
-# NOTE: There's no way to only update patched crates, so we use a heuristic
-# of updating a crucial Substrate crate (`sp-core`) to minimize the impact of
-# updating unrelated dependencies
-cargo update -p sp-core
-
-# Test Polkadot pr or master branch with this Substrate commit.
-time cargo test --workspace --release --verbose --features=runtime-benchmarks