diff --git a/.buildkite/pipeline.yml b/.buildkite/pipeline.yml
index 97219757d81c..d29544997f37 100644
--- a/.buildkite/pipeline.yml
+++ b/.buildkite/pipeline.yml
@@ -4,7 +4,7 @@ steps:
   - label: "Trigger Auditbeat"
     plugins:
       - monorepo-diff#v1.0.1:
-          diff: "git diff --name-only HEAD~1"
+          diff: "git diff --name-only origin/${GITHUB_PR_TARGET_BRANCH}...HEAD"
           watch:
             - path:
                 - auditbeat/
@@ -22,12 +22,13 @@ steps:
                   branch: "${BUILDKITE_BRANCH}"
                   env:
                     - BUILDKITE_PULL_REQUEST=${BUILDKITE_PULL_REQUEST}
+                    - BUILDKITE_PULL_REQUEST_BASE_BRANCH=${BUILDKITE_PULL_REQUEST_BASE_BRANCH}
                     - GITHUB_PR_LABELS=${GITHUB_PR_LABELS}
 
   - label: "Trigger Heartbeat"
     plugins:
       - monorepo-diff#v1.0.1:
-          diff: "git diff --name-only HEAD~1"
+          diff: "git diff --name-only origin/${GITHUB_PR_TARGET_BRANCH}...HEAD"
           watch:
             - path:
                 - heartbeat/
@@ -45,12 +46,13 @@ steps:
                   branch: "${BUILDKITE_BRANCH}"
                   env:
                     - BUILDKITE_PULL_REQUEST=${BUILDKITE_PULL_REQUEST}
+                    - BUILDKITE_PULL_REQUEST_BASE_BRANCH=${BUILDKITE_PULL_REQUEST_BASE_BRANCH}
                     - GITHUB_PR_LABELS=${GITHUB_PR_LABELS}
 
   - label: "Trigger Xpack/Dockerlogbeat"
     plugins:
       - monorepo-diff#v1.0.1:
-          diff: "git diff --name-only ${GITHUB_PR_TARGET_BRANCH}...HEAD"
+          diff: "git diff --name-only origin/${GITHUB_PR_TARGET_BRANCH}...HEAD"
           watch:
             - path:
                 - x-pack/dockerlogbeat/
@@ -68,12 +70,13 @@ steps:
                   branch: "${BUILDKITE_BRANCH}"
                   env:
                     - BUILDKITE_PULL_REQUEST=${BUILDKITE_PULL_REQUEST}
+                    - BUILDKITE_PULL_REQUEST_BASE_BRANCH=${BUILDKITE_PULL_REQUEST_BASE_BRANCH}
                     - GITHUB_PR_LABELS=${GITHUB_PR_LABELS}
 
   - label: "Trigger Metricbeat"
     plugins:
       - monorepo-diff#v1.0.1:
-          diff: "git diff --name-only ${GITHUB_PR_TARGET_BRANCH}...HEAD"
+          diff: "git diff --name-only origin/${GITHUB_PR_TARGET_BRANCH}...HEAD"
           watch:
             - path:
                 - metricbeat/
@@ -92,12 +95,13 @@ steps:
                   branch: "${BUILDKITE_BRANCH}"
                   env:
                     - BUILDKITE_PULL_REQUEST=${BUILDKITE_PULL_REQUEST}
+                    - BUILDKITE_PULL_REQUEST_BASE_BRANCH=${BUILDKITE_PULL_REQUEST_BASE_BRANCH}
                     - GITHUB_PR_LABELS=${GITHUB_PR_LABELS}
 
   - label: "Trigger Deploy/K8S"
     plugins:
       - monorepo-diff#v1.0.1:
-          diff: "git diff --name-only HEAD~1"
+          diff: "git diff --name-only origin/${GITHUB_PR_TARGET_BRANCH}...HEAD"
           watch:
             - path:
                 - .buildkite/deploy/kubernetes/**
@@ -110,4 +114,5 @@ steps:
                   branch: "${BUILDKITE_BRANCH}"
                   env:
                     - BUILDKITE_PULL_REQUEST=${BUILDKITE_PULL_REQUEST}
+                    - BUILDKITE_PULL_REQUEST_BASE_BRANCH=${BUILDKITE_PULL_REQUEST_BASE_BRANCH}
                     - GITHUB_PR_LABELS=${GITHUB_PR_LABELS}