diff --git a/generator/lib/src/generator.dart b/generator/lib/src/generator.dart
index b3b8a2ca..fa8abf0b 100644
--- a/generator/lib/src/generator.dart
+++ b/generator/lib/src/generator.dart
@@ -1867,6 +1867,9 @@ ${bodyName.displayName} == null
         final contentType = r.peek('contentType')?.stringValue;
 
         if (isFileField) {
+          if (p.type.isNullable) {
+            blocks.add(Code('if (${p.displayName} != null){'));
+          }
           final fileNameValue = r.peek('fileName')?.stringValue;
           final fileName = fileNameValue != null
               ? literalString(fileNameValue)
@@ -1907,6 +1910,9 @@ ${bodyName.displayName} == null
           } else {
             blocks.add(returnCode);
           }
+          if (p.type.isNullable) {
+            blocks.add(Code('}'));
+          }
         } else if (_displayString(p.type) == 'List<int>') {
           final optionalFile = m.parameters
                   .firstWhereOrNull((pp) => pp.displayName == p.displayName)