diff --git a/migrations/versions/fg7b8c9d0e1f_backfill_intervention_workflows.py b/migrations/versions/fg7b8c9d0e1f_backfill_intervention_workflows.py
new file mode 100644
index 0000000..8f8b3f9
--- /dev/null
+++ b/migrations/versions/fg7b8c9d0e1f_backfill_intervention_workflows.py
@@ -0,0 +1,16 @@
+"""Classe les interventions existantes par workflow."""
+from alembic import op
+import sqlalchemy as sa
+
+revision = "fg7b8c9d0e1f"
+down_revision = "ff6a7b8c9d0e"
+branch_labels = None
+depends_on = None
+
+def upgrade():
+    op.execute(sa.text("UPDATE interventions SET workflow_type='preventive' WHERE type='preventif'"))
+    op.execute(sa.text("UPDATE interventions SET workflow_type='travaux' WHERE type='amelioratif'"))
+    op.execute(sa.text("UPDATE interventions SET workflow_type='prevention' WHERE type IN ('prevention','administratif','formation')"))
+
+def downgrade():
+    op.execute(sa.text("UPDATE interventions SET workflow_type='corrective' WHERE workflow_type IN ('preventive','travaux','prevention')"))