diff --git a/tests/test_catalog_fingerprint.py b/tests/test_catalog_fingerprint.py
new file mode 100644
index 0000000..9aa49ae
--- /dev/null
+++ b/tests/test_catalog_fingerprint.py
@@ -0,0 +1,17 @@
+import hashlib
+import json
+
+from townlight_core.catalog import fingerprint
+
+
+def test_catalog_fingerprint_preserves_digest_across_database_collations():
+    canonical_rows = [
+        {"domain": "Utilities", "vendor_name": "CIS Infinity", "access_protocol": "odbc"},
+        {"domain": "Utilities", "vendor_name": "Cartegraph", "access_protocol": "rest_api"},
+    ]
+    previous_digest = hashlib.sha256(
+        json.dumps(canonical_rows, sort_keys=True, separators=(",", ":")).encode()
+    ).hexdigest()
+
+    assert fingerprint(reversed(canonical_rows)) == previous_digest
+    assert fingerprint(canonical_rows[:1]) != previous_digest
diff --git a/townlight_core/catalog/__init__.py b/townlight_core/catalog/__init__.py
index f181179..85eb53d 100644
--- a/townlight_core/catalog/__init__.py
+++ b/townlight_core/catalog/__init__.py
@@ -66,6 +66,10 @@ def unique_entries(self):
         return self
 
 
+def catalog_row_key(row):
+    return row["domain"], row["vendor_name"], row["access_protocol"]
+
+
 def normalized_rows(bundle: CatalogInput):
     return sorted(
         [
@@ -73,13 +77,15 @@ def normalized_rows(bundle: CatalogInput):
             for domain in bundle.domains
             for system in domain.systems
         ],
-        key=lambda r: (r["domain"], r["vendor_name"], r["access_protocol"]),
+        key=catalog_row_key,
     )
 
 
 def fingerprint(rows):
+    # Database collation can order the same keys differently from Python.
+    canonical_rows = sorted(rows, key=catalog_row_key)
     return hashlib.sha256(
-        json.dumps(rows, sort_keys=True, separators=(",", ":")).encode()
+        json.dumps(canonical_rows, sort_keys=True, separators=(",", ":")).encode()
     ).hexdigest()