diff --git a/server/alembic/versions/a1b8c6d4e2f9_material_items_project_list.py b/server/alembic/versions/a1b8c6d4e2f9_material_items_project_list.py
index 4661c90..0fa5f06 100644
--- a/server/alembic/versions/a1b8c6d4e2f9_material_items_project_list.py
+++ b/server/alembic/versions/a1b8c6d4e2f9_material_items_project_list.py
@@ -32,7 +32,11 @@ def upgrade() -> None:
         sa.Column('code', sa.String(length=80), nullable=False, server_default=''),
         sa.Column('description', sa.String(length=300), nullable=False, server_default=''),
         sa.Column('unit', sa.String(length=20), nullable=False, server_default=''),
-        sa.Column('active', sa.Boolean(), nullable=False, server_default=sa.text('1')),
+        # sa.true(), not sa.text('1'): SQLite coerces integer 1 to boolean,
+        # Postgres refuses it (DatatypeMismatch) - found when this migration
+        # took down the wp.controls.dev api container on 2026-08-21. The
+        # location-taxonomy migration next door had it right all along.
+        sa.Column('active', sa.Boolean(), nullable=False, server_default=sa.true()),
         sa.Column('sort', sa.Integer(), nullable=False, server_default='0'),
         sa.Column('created_at', sa.DateTime(timezone=True), nullable=True),
         sa.PrimaryKeyConstraint('id'),
diff --git a/tests/materials_check.py b/tests/materials_check.py
index c477d28..c0a1c89 100644
--- a/tests/materials_check.py
+++ b/tests/materials_check.py
@@ -54,6 +54,20 @@ def main():
     chk("locations and materials are both instances of it - not a copy beside it",
         "locList = WPListImport(" in suite and "matList = WPListImport(" in suite
         and "function locImport(dryRun){ locList.importText" in suite)
+    # The 2026-08-21 outage, pinned: a Boolean server_default of sa.text('1')
+    # passes on SQLite (which coerces 1) and crash-loops Postgres at deploy
+    # (DatatypeMismatch). Every migration must say sa.true()/sa.false().
+    import re as _re
+    bad = []
+    vdir = os.path.join(ROOT, "server", "alembic", "versions")
+    for fn in sorted(os.listdir(vdir)):
+        if not fn.endswith(".py"):
+            continue
+        for ln in open(os.path.join(vdir, fn), encoding="utf-8"):
+            if "Boolean" in ln and "server_default" in ln and                not _re.search(r"server_default=sa\.(true|false)\(\)", ln):
+                bad.append("%s: %s" % (fn, ln.strip()[:90]))
+    chk("no migration gives a Boolean a non-portable server_default "
+        "(sa.true()/sa.false() only)", not bad, ascii_(bad[:3]))
     model = open(os.path.join(ROOT, "server", "models.py"), encoding="utf-8").read()
     mat_block = model[model.find("class MaterialItem"):model.find("class WpFile")]
     cols = re.findall(r"^\s+(\w+): Mapped", mat_block, re.M)