diff --git a/.gitlab-ci.d/check-dco.py b/.gitlab-ci.d/check-dco.py
new file mode 100755
index 0000000000..632c8bcce8
--- /dev/null
+++ b/.gitlab-ci.d/check-dco.py
@@ -0,0 +1,94 @@
+#!/usr/bin/env python3
+#
+# check-dco.py: validate all commits are signed off
+#
+# Copyright (C) 2020 Red Hat, Inc.
+#
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+import os
+import os.path
+import sys
+import subprocess
+
+namespace = "qemu-project"
+if len(sys.argv) >= 2:
+    namespace = sys.argv[1]
+
+cwd = os.getcwd()
+reponame = os.path.basename(cwd)
+repourl = "https://gitlab.com/%s/%s.git" % (namespace, reponame)
+
+subprocess.check_call(["git", "remote", "add", "check-dco", repourl])
+subprocess.check_call(["git", "fetch", "check-dco", "master"],
+                      stdout=subprocess.DEVNULL,
+                      stderr=subprocess.DEVNULL)
+
+ancestor = subprocess.check_output(["git", "merge-base",
+                                    "check-dco/master", "HEAD"],
+                                   universal_newlines=True)
+
+ancestor = ancestor.strip()
+
+subprocess.check_call(["git", "remote", "rm", "check-dco"])
+
+errors = False
+
+print("\nChecking for 'Signed-off-by: NAME <EMAIL>' " +
+      "on all commits since %s...\n" % ancestor)
+
+log = subprocess.check_output(["git", "log", "--format=%H %s",
+                               ancestor + "..."],
+                              universal_newlines=True)
+
+if log == "":
+    commits = []
+else:
+    commits = [[c[0:40], c[41:]] for c in log.strip().split("\n")]
+
+for sha, subject in commits:
+
+    msg = subprocess.check_output(["git", "show", "-s", sha],
+                                  universal_newlines=True)
+    lines = msg.strip().split("\n")
+
+    print("🔍 %s %s" % (sha, subject))
+    sob = False
+    for line in lines:
+        if "Signed-off-by:" in line:
+            sob = True
+            if "localhost" in line:
+                print("    ❌ FAIL: bad email in %s" % line)
+                errors = True
+
+    if not sob:
+        print("    ❌ FAIL missing Signed-off-by tag")
+        errors = True
+
+if errors:
+    print("""
+
+❌ ERROR: One or more commits are missing a valid Signed-off-By tag.
+
+
+This project requires all contributors to assert that their contributions
+are provided in compliance with the terms of the Developer's Certificate
+of Origin 1.1 (DCO):
+
+  https://developercertificate.org/
+
+To indicate acceptance of the DCO every commit must have a tag
+
+  Signed-off-by: REAL NAME <EMAIL>
+
+This can be achieved by passing the "-s" flag to the "git commit" command.
+
+To bulk update all commits on current branch "git rebase" can be used:
+
+  git rebase -i master -x 'git commit --amend --no-edit -s'
+
+""")
+
+    sys.exit(1)
+
+sys.exit(0)
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index f1e18d3e90..40805740a6 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -411,3 +411,13 @@ check-patch:
   variables:
     GIT_DEPTH: 1000
   allow_failure: true
+
+check-dco:
+  stage: build
+  image: $CI_REGISTRY_IMAGE/qemu/centos8:latest
+  script: .gitlab-ci.d/check-dco.py
+  except:
+    variables:
+      - $CI_PROJECT_NAMESPACE == 'qemu-project' && $CI_COMMIT_BRANCH == 'master'
+  variables:
+    GIT_DEPTH: 1000