diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index f727456158ee..b1883f9e9687 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -32,7 +32,7 @@ variables:
   CI_IMAGE:                        "paritytech/ci-linux:production"
   DOCKER_OS:                       "debian:stretch"
   ARCH:                            "x86_64"
-  ZOMBIENET_IMAGE:                 "docker.io/paritytech/zombienet:v1.2.25"
+  ZOMBIENET_IMAGE:                 "docker.io/paritytech/zombienet:v1.2.50"
   PIPELINE_SCRIPTS_TAG:            "v0.4"
 
 default:
@@ -826,7 +826,7 @@ zombienet-tests-malus-dispute-valid:
 
 zombienet-tests-deregister-register-validator:
   stage:                           stage3
-  image:                           "docker.io/paritytech/zombienet:v1.2.47"
+  image:                           "${ZOMBIENET_IMAGE}"
   <<:                              *kubernetes-env
   <<:                              *zombienet-refs
   needs:
@@ -851,6 +851,31 @@ zombienet-tests-deregister-register-validator:
   tags:
     - zombienet-polkadot-integration-test
 
+zombienet-tests-beefy-and-mmr:
+  stage:                           stage3
+  <<:                              *kubernetes-env
+  <<:                              *zombienet-refs
+  image:                           "${ZOMBIENET_IMAGE}"
+  needs:
+    - job:                         publish-polkadot-debug-image
+  variables:
+    GH_DIR:                        "https://github.com/paritytech/polkadot/tree/${CI_COMMIT_SHORT_SHA}/zombienet_tests/functional"
+  before_script:
+    - echo "Zombie-net Tests Config"
+    - echo "${ZOMBIENET_IMAGE_NAME}"
+    - echo "${PARACHAINS_IMAGE_NAME} ${PARACHAINS_IMAGE_TAG}"
+    - echo "${GH_DIR}"
+    - export DEBUG=zombie*
+    - export ZOMBIENET_INTEGRATION_TEST_IMAGE=${PARACHAINS_IMAGE_NAME}:${PARACHAINS_IMAGE_TAG}
+  script:
+    - /home/nonroot/zombie-net/scripts/ci/run-test-env-manager.sh
+      --github-remote-dir="${GH_DIR}"
+      --test="0003-beefy-and-mmr.feature"
+  allow_failure:                   true
+  retry: 2
+  tags:
+    - zombienet-polkadot-integration-test
+
 #### stage:                        stage4
 
 publish-rustdoc:
diff --git a/zombienet_tests/functional/0003-beefy-and-mmr.feature b/zombienet_tests/functional/0003-beefy-and-mmr.feature
new file mode 100644
index 000000000000..2736cb60cc35
--- /dev/null
+++ b/zombienet_tests/functional/0003-beefy-and-mmr.feature
@@ -0,0 +1,44 @@
+Description: Test BEEFY voting and finality, test MMR proofs. Assumes Rococo sessions of 1 minute.
+Network: ./0003-beefy-and-mmr.toml
+Creds: config
+
+# Some sanity checks.
+validator-0: is up
+validator-1: is up
+validator-2: is up
+
+# Check authority status.
+validator-0: reports node_roles is 4
+validator-1: reports node_roles is 4
+validator-2: reports node_roles is 4
+
+# BEEFY sanity checks.
+validator-0: reports substrate_beefy_validator_set_id is 0
+validator-1: reports substrate_beefy_validator_set_id is 0
+validator-2: reports substrate_beefy_validator_set_id is 0
+
+# Verify voting happens and 1st mandatory block is finalized within 1st session.
+validator-0: reports substrate_beefy_best_block is at least 1 within 60 seconds
+validator-1: reports substrate_beefy_best_block is at least 1 within 60 seconds
+validator-2: reports substrate_beefy_best_block is at least 1 within 60 seconds
+
+# Verify validator sets get changed on new sessions.
+validator-0: reports substrate_beefy_validator_set_id is at least 1 within 70 seconds
+validator-1: reports substrate_beefy_validator_set_id is at least 1 within 70 seconds
+validator-2: reports substrate_beefy_validator_set_id is at least 1 within 70 seconds
+# Check next session too.
+validator-0: reports substrate_beefy_validator_set_id is at least 2 within 130 seconds
+validator-1: reports substrate_beefy_validator_set_id is at least 2 within 130 seconds
+validator-2: reports substrate_beefy_validator_set_id is at least 2 within 130 seconds
+
+# Verify voting happens and blocks are being finalized for new sessions too:
+# since we verified we're at least in the 3rd session, verify BEEFY finalized mandatory #21.
+validator-0: reports substrate_beefy_best_block is at least 21 within 130 seconds
+validator-1: reports substrate_beefy_best_block is at least 21 within 130 seconds
+validator-2: reports substrate_beefy_best_block is at least 21 within 130 seconds
+
+# TODO 1: Custom JS to test BEEFY RPCs
+
+# TODO 2: Custom JS to test MMR RPCs
+
+# TODO 3: once zombienet/#227 is implemented: pause+resume nodes to test Justifications Import
diff --git a/zombienet_tests/functional/0003-beefy-and-mmr.toml b/zombienet_tests/functional/0003-beefy-and-mmr.toml
new file mode 100644
index 000000000000..6ac2ec0af7ff
--- /dev/null
+++ b/zombienet_tests/functional/0003-beefy-and-mmr.toml
@@ -0,0 +1,12 @@
+[settings]
+timeout = 1000
+
+[relaychain]
+default_image = "{{ZOMBIENET_INTEGRATION_TEST_IMAGE}}"
+chain = "rococo-local"
+command = "polkadot"
+
+[[relaychain.node_groups]]
+name = "validator"
+count = 3
+args = ["--log=beefy=debug", "--beefy", "--enable-offchain-indexing=true"]