diff --git a/ormar/__init__.py b/ormar/__init__.py
index 0540e46..aa3278e 100644
--- a/ormar/__init__.py
+++ b/ormar/__init__.py
@@ -76,7 +76,7 @@ class UndefinedType:  # pragma no cover
 
 Undefined = UndefinedType()
 
-__version__ = "0.10.8"
+__version__ = "0.10.9"
 __all__ = [
     "Integer",
     "BigInteger",
diff --git a/ormar/models/helpers/validation.py b/ormar/models/helpers/validation.py
index c86687e..1ce2a9f 100644
--- a/ormar/models/helpers/validation.py
+++ b/ormar/models/helpers/validation.py
@@ -251,9 +251,10 @@ def overwrite_binary_format(schema: Dict[str, Any], model: Type["Model"]) -> Non
             and model.Meta.model_fields[field_id].represent_as_base64_str
         ):
             prop["format"] = "base64"
-            prop["enum"] = [
-                base64.b64encode(choice).decode() for choice in prop["enum"]
-            ]
+            if prop.get("enum"):
+                prop["enum"] = [
+                    base64.b64encode(choice).decode() for choice in prop.get("enum", [])
+                ]
 
 
 def construct_modify_schema_function(fields_with_choices: List) -> SchemaExtraCallable:
diff --git a/requirements.txt b/requirements.txt
index 88d9420..d6b7929 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -7,7 +7,7 @@ typing_extensions>=3.7,<=3.7.4.3
 orjson
 cryptography
 
-# Async database drivers
+# Async database driversy
 aiomysql
 aiosqlite
 aiopg