diff --git a/openstates/importers/base.py b/openstates/importers/base.py
index 7ab80fb7..1198b0c5 100644
--- a/openstates/importers/base.py
+++ b/openstates/importers/base.py
@@ -532,16 +532,20 @@ def apply_transformers(
         if transformers is None:
             transformers = self.cached_transformers
 
-        for key, key_transformers in transformers.items():
-            if key not in data:
-                continue
-            if isinstance(key_transformers, list):
-                for transformer in key_transformers:
-                    data[key] = transformer(data[key])
-            elif isinstance(key_transformers, dict):
-                self.apply_transformers(data[key], key_transformers)
-            else:
-                data[key] = key_transformers(data[key])
+        if isinstance(data, list):
+            for data_item in data:
+                self.apply_transformers(data_item, transformers)
+        else:
+            for key, key_transformers in transformers.items():
+                if key not in data:
+                    continue
+                if isinstance(key_transformers, list):
+                    for transformer in key_transformers:
+                        data[key] = transformer(data[key])
+                elif isinstance(key_transformers, dict):
+                    self.apply_transformers(data[key], key_transformers)
+                else:
+                    data[key] = key_transformers(data[key])
 
         return data
 
diff --git a/openstates/settings.py b/openstates/settings.py
index e1763ab0..b1551bbd 100644
--- a/openstates/settings.py
+++ b/openstates/settings.py
@@ -24,7 +24,16 @@
 CACHE_DIR = os.path.join(os.getcwd(), "_cache")
 SCRAPED_DATA_DIR = os.path.join(os.getcwd(), "_data")
 
-IMPORT_TRANSFORMERS = {"bill": {"identifier": transformers.fix_bill_id}}
+IMPORT_TRANSFORMERS = {
+    "bill": {
+        "identifier": transformers.fix_bill_id,
+        "documents": {"note": transformers.truncate_300},  # TODO remove when db migration done
+        "versions": {"note": transformers.truncate_300},  # TODO remove when db migration done
+    },
+    "event": {
+        "media": {"note": transformers.truncate_300},  # TODO remove when db migration done
+    }
+}
 
 # Django settings
 LOGGING = {
diff --git a/openstates/utils/transformers.py b/openstates/utils/transformers.py
index cab4ef1b..d82cd3f8 100644
--- a/openstates/utils/transformers.py
+++ b/openstates/utils/transformers.py
@@ -19,3 +19,7 @@ def fix_bill_id(bill_id: str) -> str:
 
 def collapse_whitespace(value: str) -> str:
     return _whitespace_re.sub(" ", value)
+
+
+def truncate_300(value: str) -> str:
+    return value[:300]