diff --git a/reana_db/alembic/versions/20240531_0959_86435bb00714_foreign_key_for_workflow_uuid_of_job.py b/reana_db/alembic/versions/20240531_0959_86435bb00714_foreign_key_for_workflow_uuid_of_job.py
new file mode 100644
index 0000000..bf8d11c
--- /dev/null
+++ b/reana_db/alembic/versions/20240531_0959_86435bb00714_foreign_key_for_workflow_uuid_of_job.py
@@ -0,0 +1,64 @@
+"""Foreign key for workflow_uuid of Job.
+
+Revision ID: 86435bb00714
+Revises: eb5309f3d8ee
+Create Date: 2024-05-31 09:59:18.951074
+
+"""
+
+from alembic import op
+import sqlalchemy as sa
+from sqlalchemy.dialects import postgresql
+
+# revision identifiers, used by Alembic.
+revision = "86435bb00714"
+down_revision = "eb5309f3d8ee"
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    """Upgrade to 86435bb00714."""
+    job_table = sa.sql.table("job", sa.sql.column("workflow_uuid"), schema="__reana")
+    workflow_table = sa.sql.table("workflow", sa.sql.column("id_"), schema="__reana")
+
+    # 1. delete jobs which refer to non-existing workflows
+    op.execute(
+        job_table.delete().where(
+            job_table.c.workflow_uuid.notin_(sa.select([workflow_table.c.id_]))
+        )
+    )
+
+    # 2. alter column to make it non-nullable
+    op.alter_column(
+        "job",
+        "workflow_uuid",
+        existing_type=postgresql.UUID(),
+        nullable=False,
+        schema="__reana",
+    )
+
+    # 3. create foreign key constraint
+    op.create_foreign_key(
+        "fk_job_workflow_uuid_workflow",
+        "job",
+        "workflow",
+        ["workflow_uuid"],
+        ["id_"],
+        source_schema="__reana",
+        referent_schema="__reana",
+    )
+
+
+def downgrade():
+    """Downgrade to eb5309f3d8ee."""
+    op.drop_constraint(
+        "fk_job_workflow_uuid_workflow", "job", schema="__reana", type_="foreignkey"
+    )
+    op.alter_column(
+        "job",
+        "workflow_uuid",
+        existing_type=postgresql.UUID(),
+        nullable=True,
+        schema="__reana",
+    )
diff --git a/reana_db/models.py b/reana_db/models.py
index 36609fc..c0b0206 100644
--- a/reana_db/models.py
+++ b/reana_db/models.py
@@ -823,7 +823,11 @@ class Job(Base, Timestamp):
 
     id_ = Column(UUIDType, primary_key=True, default=generate_uuid)
     backend_job_id = Column(String(256))
-    workflow_uuid = Column(UUIDType)
+    workflow_uuid = Column(
+        UUIDType,
+        ForeignKey("__reana.workflow.id_"),
+        nullable=False,
+    )
     status = Column(Enum(JobStatus), default=JobStatus.created)
     compute_backend = Column(String(30))
     cvmfs_mounts = Column(Text)