diff --git a/reana_db/models.py b/reana_db/models.py
index 5f2abe7..98a98c0 100644
--- a/reana_db/models.py
+++ b/reana_db/models.py
@@ -293,12 +293,19 @@ class RunStatus(enum.Enum):
     deleted = 4
     stopped = 5
     queued = 6
+    pending = 7
 
 
 ALLOWED_WORKFLOW_STATUS_TRANSITIONS = [
-    # Creation
+    # Created
     (RunStatus.created, RunStatus.deleted),
-    (RunStatus.created, RunStatus.running),
+    (RunStatus.created, RunStatus.queued),
+    # Queued
+    (RunStatus.queued, RunStatus.deleted),
+    (RunStatus.queued, RunStatus.pending),
+    # Pending
+    (RunStatus.pending, RunStatus.running),
+    (RunStatus.pending, RunStatus.deleted),
     # Running
     (RunStatus.running, RunStatus.failed),
     (RunStatus.running, RunStatus.finished),
diff --git a/setup.py b/setup.py
index 06a1d3f..30d3ef0 100755
--- a/setup.py
+++ b/setup.py
@@ -41,7 +41,7 @@
 install_requires = [
     "alembic>=1.4.2",
     "psycopg2-binary>=2.6.1",
-    "SQLAlchemy>=1.2.7",
+    "SQLAlchemy>=1.2.7,<1.4.0",
     'sqlalchemy-utils>=0.35.0 ; python_version>="3"',
     'sqlalchemy-utils<=0.36.3 ; python_version=="2.7"',
     "cryptography>=2.9.2",  # Required by sqlalchemy_utils.EncryptedType
diff --git a/tests/test_models.py b/tests/test_models.py
index 8768cdd..1d5f664 100644
--- a/tests/test_models.py
+++ b/tests/test_models.py
@@ -89,6 +89,16 @@ def test_workflow_run_number_assignment(db, session, new_user):
         (RunStatus.created, RunStatus.failed, False),
         (RunStatus.created, RunStatus.finished, False),
         (RunStatus.created, RunStatus.stopped, False),
+        (RunStatus.created, RunStatus.running, False),
+        (RunStatus.created, RunStatus.pending, False),
+        (RunStatus.queued, RunStatus.failed, False),
+        (RunStatus.queued, RunStatus.finished, False),
+        (RunStatus.queued, RunStatus.stopped, False),
+        (RunStatus.queued, RunStatus.running, False),
+        (RunStatus.pending, RunStatus.failed, False),
+        (RunStatus.pending, RunStatus.finished, False),
+        (RunStatus.pending, RunStatus.stopped, False),
+        (RunStatus.pending, RunStatus.created, False),
         (RunStatus.deleted, RunStatus.created, False),
         (RunStatus.deleted, RunStatus.failed, False),
         (RunStatus.deleted, RunStatus.finished, False),