diff --git a/openstack_releases/cmds/validate.py b/openstack_releases/cmds/validate.py
index 3b171e2d1c..a7100a6ae9 100644
--- a/openstack_releases/cmds/validate.py
+++ b/openstack_releases/cmds/validate.py
@@ -432,7 +432,7 @@ def validate_series_eol(deliv, context):
 @skip_existing_tags
 @applies_to_released
 def validate_series_em(deliv, context):
-    "The EM tag should be applied to the previous release."
+    """The EM tag should be applied to the previous release."""
 
     current_release = deliv.releases[-1]
 
@@ -441,6 +441,13 @@ def validate_series_em(deliv, context):
               'a series as extended-maintenance')
         return
 
+    if len(deliv.releases) == 1:
+        context.error('at least one release will have to been done to '
+                      'mark as extended-maintenance')
+        print('This deliverable may need to be cleaned up if a '
+              'release was not actually done for the series.')
+        return
+
     _require_tag_on_all_repos(
         deliv,
         current_release,
@@ -448,6 +455,23 @@ def validate_series_em(deliv, context):
         context,
     )
 
+    # Make sure we are taking the last release
+    previous_release = deliv.releases[-2]
+    for project in deliv.known_repo_names:
+        current_proj = current_release.project(project)
+        previous_proj = previous_release.project(project)
+
+        if current_proj is None or previous_proj is None:
+            # Error will be picked up above
+            continue
+
+        current_hash = current_proj.hash
+        previous_hash = previous_proj.hash
+        if current_hash != previous_hash:
+            context.error('EM tag must match the last release, tagging '
+                          '%s, last release %s' %
+                          (current_hash, previous_hash))
+
 
 @skip_em_eol_tags
 def validate_bugtracker(deliv, context):
diff --git a/openstack_releases/deliverable.py b/openstack_releases/deliverable.py
index b7e3e56a90..38bb3d7961 100644
--- a/openstack_releases/deliverable.py
+++ b/openstack_releases/deliverable.py
@@ -300,6 +300,11 @@ class Release(object):
     def projects(self):
         return sorted(self._projects.values())
 
+    def project(self, repo):
+        if repo in self._projects:
+            return self._projects[repo]
+        return None
+
     @property
     def diff_start(self):
         return self._data.get('diff-start')
diff --git a/openstack_releases/tests/test_validate.py b/openstack_releases/tests/test_validate.py
index b5a5646960..5035de74bd 100644
--- a/openstack_releases/tests/test_validate.py
+++ b/openstack_releases/tests/test_validate.py
@@ -3258,6 +3258,10 @@ class TestValidateSeriesEM(base.BaseTestCase):
         ---
         team: Release Management
         releases:
+          - version: 1.2.3
+            projects:
+              - repo: openstack/automaton
+                hash: be2885f544637e6ee6139df7dc7bf937925804dd
           - version: newton-em
             projects:
               - repo: openstack/automaton
@@ -3277,15 +3281,111 @@ class TestValidateSeriesEM(base.BaseTestCase):
         self.assertEqual(0, len(self.ctx.warnings))
         self.assertEqual(0, len(self.ctx.errors))
 
+    def test_em_no_releases(self):
+        deliverable_data = yamlutils.loads(textwrap.dedent('''
+        ---
+        team: Release Management
+        releases:
+          - version: newton-em
+            projects:
+              - repo: openstack/automaton
+                hash: be2885f544637e6ee6139df7dc7bf937925804dd
+        '''))
+        deliv = deliverable.Deliverable(
+            None,
+            'newton',
+            'test',
+            deliverable_data,
+        )
+        validate.validate_series_em(
+            deliv,
+            self.ctx,
+        )
+        self.ctx.show_summary()
+        self.assertEqual(0, len(self.ctx.warnings))
+        self.assertEqual(1, len(self.ctx.errors))
+
+    def test_em_not_matching_last_release(self):
+        deliverable_data = yamlutils.loads(textwrap.dedent('''
+        ---
+        team: Release Management
+        releases:
+          - version: 1.2.3
+            projects:
+              - repo: openstack/automaton
+                hash: be2885f544637e6ee6139df7dc7bf937925804dd
+          - version: 1.2.4
+            projects:
+              - repo: openstack/automaton
+                hash: beef85f544637e6ee6139df7dc7bf937925804dd
+          - version: newton-em
+            projects:
+              - repo: openstack/automaton
+                hash: be2885f544637e6ee6139df7dc7bf937925804dd
+        repository-settings:
+          openstack/automaton: {}
+        '''))
+        deliv = deliverable.Deliverable(
+            None,
+            'newton',
+            'test',
+            deliverable_data,
+        )
+        validate.validate_series_em(
+            deliv,
+            self.ctx,
+        )
+        self.ctx.show_summary()
+        self.assertEqual(0, len(self.ctx.warnings))
+        self.assertEqual(1, len(self.ctx.errors))
+
+    def test_em_matches_last_release(self):
+        deliverable_data = yamlutils.loads(textwrap.dedent('''
+        ---
+        team: Release Management
+        releases:
+          - version: 1.2.3
+            projects:
+              - repo: openstack/automaton
+                hash: be2885f544637e6ee6139df7dc7bf937925804dd
+          - version: 1.2.4
+            projects:
+              - repo: openstack/automaton
+                hash: beef85f544637e6ee6139df7dc7bf937925804dd
+          - version: newton-em
+            projects:
+              - repo: openstack/automaton
+                hash: beef85f544637e6ee6139df7dc7bf937925804dd
+        repository-settings:
+          openstack/automaton: {}
+        '''))
+        deliv = deliverable.Deliverable(
+            None,
+            'newton',
+            'test',
+            deliverable_data,
+        )
+        validate.validate_series_em(
+            deliv,
+            self.ctx,
+        )
+        self.ctx.show_summary()
+        self.assertEqual(0, len(self.ctx.warnings))
+        self.assertEqual(0, len(self.ctx.errors))
+
     def test_em_missing_repo(self):
         deliverable_data = yamlutils.loads(textwrap.dedent('''
         ---
         team: Release Management
         releases:
+          - version: 1.2.3
+            projects:
+              - repo: openstack/automaton
+                hash: be2885f544637e6ee6139df7dc7bf937925804dd
           - version: newton-em
             projects:
               - repo: openstack/automaton
-                hash: ce2885f544637e6ee6139df7dc7bf937925804dd
+                hash: be2885f544637e6ee6139df7dc7bf937925804dd
         repository-settings:
           openstack/automaton: {}
           openstack/release-test: {}