diff --git a/protobuf-codegen/src/message.rs b/protobuf-codegen/src/message.rs
index 862501343..ced60dd16 100644
--- a/protobuf-codegen/src/message.rs
+++ b/protobuf-codegen/src/message.rs
@@ -386,8 +386,7 @@ impl<'a> MessageGen<'a> {
             if self.serde_derive_enabled() {
                 w.write_line("#[serde(skip)]");
             }
-            // TODO: make public
-            w.field_decl("unknown_fields", "::protobuf::UnknownFields");
+            w.pub_field_decl("unknown_fields", "::protobuf::UnknownFields");
             if self.serde_derive_enabled() {
                 w.write_line("#[serde(skip)]");
             }
diff --git a/protobuf/src/descriptor.rs b/protobuf/src/descriptor.rs
index 116d30c7a..8d0a6bb2c 100644
--- a/protobuf/src/descriptor.rs
+++ b/protobuf/src/descriptor.rs
@@ -26,7 +26,7 @@ pub struct FileDescriptorSet {
     // message fields
     file: ::protobuf::RepeatedField<FileDescriptorProto>,
     // special fields
-    unknown_fields: ::protobuf::UnknownFields,
+    pub unknown_fields: ::protobuf::UnknownFields,
     cached_size: ::protobuf::CachedSize,
 }
 
@@ -194,7 +194,7 @@ pub struct FileDescriptorProto {
     source_code_info: ::protobuf::SingularPtrField<SourceCodeInfo>,
     syntax: ::protobuf::SingularField<::std::string::String>,
     // special fields
-    unknown_fields: ::protobuf::UnknownFields,
+    pub unknown_fields: ::protobuf::UnknownFields,
     cached_size: ::protobuf::CachedSize,
 }
 
@@ -892,7 +892,7 @@ pub struct DescriptorProto {
     reserved_range: ::protobuf::RepeatedField<DescriptorProto_ReservedRange>,
     reserved_name: ::protobuf::RepeatedField<::std::string::String>,
     // special fields
-    unknown_fields: ::protobuf::UnknownFields,
+    pub unknown_fields: ::protobuf::UnknownFields,
     cached_size: ::protobuf::CachedSize,
 }
 
@@ -1486,7 +1486,7 @@ pub struct DescriptorProto_ExtensionRange {
     start: ::std::option::Option<i32>,
     end: ::std::option::Option<i32>,
     // special fields
-    unknown_fields: ::protobuf::UnknownFields,
+    pub unknown_fields: ::protobuf::UnknownFields,
     cached_size: ::protobuf::CachedSize,
 }
 
@@ -1674,7 +1674,7 @@ pub struct DescriptorProto_ReservedRange {
     start: ::std::option::Option<i32>,
     end: ::std::option::Option<i32>,
     // special fields
-    unknown_fields: ::protobuf::UnknownFields,
+    pub unknown_fields: ::protobuf::UnknownFields,
     cached_size: ::protobuf::CachedSize,
 }
 
@@ -1870,7 +1870,7 @@ pub struct FieldDescriptorProto {
     json_name: ::protobuf::SingularField<::std::string::String>,
     options: ::protobuf::SingularPtrField<FieldOptions>,
     // special fields
-    unknown_fields: ::protobuf::UnknownFields,
+    pub unknown_fields: ::protobuf::UnknownFields,
     cached_size: ::protobuf::CachedSize,
 }
 
@@ -2595,7 +2595,7 @@ pub struct OneofDescriptorProto {
     name: ::protobuf::SingularField<::std::string::String>,
     options: ::protobuf::SingularPtrField<OneofOptions>,
     // special fields
-    unknown_fields: ::protobuf::UnknownFields,
+    pub unknown_fields: ::protobuf::UnknownFields,
     cached_size: ::protobuf::CachedSize,
 }
 
@@ -2814,7 +2814,7 @@ pub struct EnumDescriptorProto {
     value: ::protobuf::RepeatedField<EnumValueDescriptorProto>,
     options: ::protobuf::SingularPtrField<EnumOptions>,
     // special fields
-    unknown_fields: ::protobuf::UnknownFields,
+    pub unknown_fields: ::protobuf::UnknownFields,
     cached_size: ::protobuf::CachedSize,
 }
 
@@ -3081,7 +3081,7 @@ pub struct EnumValueDescriptorProto {
     number: ::std::option::Option<i32>,
     options: ::protobuf::SingularPtrField<EnumValueOptions>,
     // special fields
-    unknown_fields: ::protobuf::UnknownFields,
+    pub unknown_fields: ::protobuf::UnknownFields,
     cached_size: ::protobuf::CachedSize,
 }
 
@@ -3339,7 +3339,7 @@ pub struct ServiceDescriptorProto {
     method: ::protobuf::RepeatedField<MethodDescriptorProto>,
     options: ::protobuf::SingularPtrField<ServiceOptions>,
     // special fields
-    unknown_fields: ::protobuf::UnknownFields,
+    pub unknown_fields: ::protobuf::UnknownFields,
     cached_size: ::protobuf::CachedSize,
 }
 
@@ -3609,7 +3609,7 @@ pub struct MethodDescriptorProto {
     client_streaming: ::std::option::Option<bool>,
     server_streaming: ::std::option::Option<bool>,
     // special fields
-    unknown_fields: ::protobuf::UnknownFields,
+    pub unknown_fields: ::protobuf::UnknownFields,
     cached_size: ::protobuf::CachedSize,
 }
 
@@ -4022,7 +4022,7 @@ pub struct FileOptions {
     csharp_namespace: ::protobuf::SingularField<::std::string::String>,
     uninterpreted_option: ::protobuf::RepeatedField<UninterpretedOption>,
     // special fields
-    unknown_fields: ::protobuf::UnknownFields,
+    pub unknown_fields: ::protobuf::UnknownFields,
     cached_size: ::protobuf::CachedSize,
 }
 
@@ -4843,7 +4843,7 @@ pub struct MessageOptions {
     map_entry: ::std::option::Option<bool>,
     uninterpreted_option: ::protobuf::RepeatedField<UninterpretedOption>,
     // special fields
-    unknown_fields: ::protobuf::UnknownFields,
+    pub unknown_fields: ::protobuf::UnknownFields,
     cached_size: ::protobuf::CachedSize,
 }
 
@@ -5162,7 +5162,7 @@ pub struct FieldOptions {
     weak: ::std::option::Option<bool>,
     uninterpreted_option: ::protobuf::RepeatedField<UninterpretedOption>,
     // special fields
-    unknown_fields: ::protobuf::UnknownFields,
+    pub unknown_fields: ::protobuf::UnknownFields,
     cached_size: ::protobuf::CachedSize,
 }
 
@@ -5649,7 +5649,7 @@ pub struct OneofOptions {
     // message fields
     uninterpreted_option: ::protobuf::RepeatedField<UninterpretedOption>,
     // special fields
-    unknown_fields: ::protobuf::UnknownFields,
+    pub unknown_fields: ::protobuf::UnknownFields,
     cached_size: ::protobuf::CachedSize,
 }
 
@@ -5808,7 +5808,7 @@ pub struct EnumOptions {
     deprecated: ::std::option::Option<bool>,
     uninterpreted_option: ::protobuf::RepeatedField<UninterpretedOption>,
     // special fields
-    unknown_fields: ::protobuf::UnknownFields,
+    pub unknown_fields: ::protobuf::UnknownFields,
     cached_size: ::protobuf::CachedSize,
 }
 
@@ -6044,7 +6044,7 @@ pub struct EnumValueOptions {
     deprecated: ::std::option::Option<bool>,
     uninterpreted_option: ::protobuf::RepeatedField<UninterpretedOption>,
     // special fields
-    unknown_fields: ::protobuf::UnknownFields,
+    pub unknown_fields: ::protobuf::UnknownFields,
     cached_size: ::protobuf::CachedSize,
 }
 
@@ -6241,7 +6241,7 @@ pub struct ServiceOptions {
     deprecated: ::std::option::Option<bool>,
     uninterpreted_option: ::protobuf::RepeatedField<UninterpretedOption>,
     // special fields
-    unknown_fields: ::protobuf::UnknownFields,
+    pub unknown_fields: ::protobuf::UnknownFields,
     cached_size: ::protobuf::CachedSize,
 }
 
@@ -6438,7 +6438,7 @@ pub struct MethodOptions {
     deprecated: ::std::option::Option<bool>,
     uninterpreted_option: ::protobuf::RepeatedField<UninterpretedOption>,
     // special fields
-    unknown_fields: ::protobuf::UnknownFields,
+    pub unknown_fields: ::protobuf::UnknownFields,
     cached_size: ::protobuf::CachedSize,
 }
 
@@ -6640,7 +6640,7 @@ pub struct UninterpretedOption {
     string_value: ::protobuf::SingularField<::std::vec::Vec<u8>>,
     aggregate_value: ::protobuf::SingularField<::std::string::String>,
     // special fields
-    unknown_fields: ::protobuf::UnknownFields,
+    pub unknown_fields: ::protobuf::UnknownFields,
     cached_size: ::protobuf::CachedSize,
 }
 
@@ -7071,7 +7071,7 @@ pub struct UninterpretedOption_NamePart {
     name_part: ::protobuf::SingularField<::std::string::String>,
     is_extension: ::std::option::Option<bool>,
     // special fields
-    unknown_fields: ::protobuf::UnknownFields,
+    pub unknown_fields: ::protobuf::UnknownFields,
     cached_size: ::protobuf::CachedSize,
 }
 
@@ -7277,7 +7277,7 @@ pub struct SourceCodeInfo {
     // message fields
     location: ::protobuf::RepeatedField<SourceCodeInfo_Location>,
     // special fields
-    unknown_fields: ::protobuf::UnknownFields,
+    pub unknown_fields: ::protobuf::UnknownFields,
     cached_size: ::protobuf::CachedSize,
 }
 
@@ -7438,7 +7438,7 @@ pub struct SourceCodeInfo_Location {
     trailing_comments: ::protobuf::SingularField<::std::string::String>,
     leading_detached_comments: ::protobuf::RepeatedField<::std::string::String>,
     // special fields
-    unknown_fields: ::protobuf::UnknownFields,
+    pub unknown_fields: ::protobuf::UnknownFields,
     cached_size: ::protobuf::CachedSize,
 }
 
@@ -7781,7 +7781,7 @@ pub struct GeneratedCodeInfo {
     // message fields
     annotation: ::protobuf::RepeatedField<GeneratedCodeInfo_Annotation>,
     // special fields
-    unknown_fields: ::protobuf::UnknownFields,
+    pub unknown_fields: ::protobuf::UnknownFields,
     cached_size: ::protobuf::CachedSize,
 }
 
@@ -7941,7 +7941,7 @@ pub struct GeneratedCodeInfo_Annotation {
     begin: ::std::option::Option<i32>,
     end: ::std::option::Option<i32>,
     // special fields
-    unknown_fields: ::protobuf::UnknownFields,
+    pub unknown_fields: ::protobuf::UnknownFields,
     cached_size: ::protobuf::CachedSize,
 }
 
diff --git a/protobuf/src/plugin.rs b/protobuf/src/plugin.rs
index 873d76d64..6272765e3 100644
--- a/protobuf/src/plugin.rs
+++ b/protobuf/src/plugin.rs
@@ -28,7 +28,7 @@ pub struct CodeGeneratorRequest {
     parameter: ::protobuf::SingularField<::std::string::String>,
     proto_file: ::protobuf::RepeatedField<::protobuf::descriptor::FileDescriptorProto>,
     // special fields
-    unknown_fields: ::protobuf::UnknownFields,
+    pub unknown_fields: ::protobuf::UnknownFields,
     cached_size: ::protobuf::CachedSize,
 }
 
@@ -278,7 +278,7 @@ pub struct CodeGeneratorResponse {
     error: ::protobuf::SingularField<::std::string::String>,
     file: ::protobuf::RepeatedField<CodeGeneratorResponse_File>,
     // special fields
-    unknown_fields: ::protobuf::UnknownFields,
+    pub unknown_fields: ::protobuf::UnknownFields,
     cached_size: ::protobuf::CachedSize,
 }
 
@@ -489,7 +489,7 @@ pub struct CodeGeneratorResponse_File {
     insertion_point: ::protobuf::SingularField<::std::string::String>,
     content: ::protobuf::SingularField<::std::string::String>,
     // special fields
-    unknown_fields: ::protobuf::UnknownFields,
+    pub unknown_fields: ::protobuf::UnknownFields,
     cached_size: ::protobuf::CachedSize,
 }
 
diff --git a/protobuf/src/well_known_types/any.rs b/protobuf/src/well_known_types/any.rs
index ca64a59ad..fd4634d76 100644
--- a/protobuf/src/well_known_types/any.rs
+++ b/protobuf/src/well_known_types/any.rs
@@ -27,7 +27,7 @@ pub struct Any {
     pub type_url: ::std::string::String,
     pub value: ::std::vec::Vec<u8>,
     // special fields
-    unknown_fields: ::protobuf::UnknownFields,
+    pub unknown_fields: ::protobuf::UnknownFields,
     cached_size: ::protobuf::CachedSize,
 }
 
diff --git a/protobuf/src/well_known_types/api.rs b/protobuf/src/well_known_types/api.rs
index b5eddcb16..bd220edd3 100644
--- a/protobuf/src/well_known_types/api.rs
+++ b/protobuf/src/well_known_types/api.rs
@@ -32,7 +32,7 @@ pub struct Api {
     pub mixins: ::protobuf::RepeatedField<Mixin>,
     pub syntax: ::protobuf::well_known_types::Syntax,
     // special fields
-    unknown_fields: ::protobuf::UnknownFields,
+    pub unknown_fields: ::protobuf::UnknownFields,
     cached_size: ::protobuf::CachedSize,
 }
 
@@ -459,7 +459,7 @@ pub struct Method {
     pub options: ::protobuf::RepeatedField<::protobuf::well_known_types::Option>,
     pub syntax: ::protobuf::well_known_types::Syntax,
     // special fields
-    unknown_fields: ::protobuf::UnknownFields,
+    pub unknown_fields: ::protobuf::UnknownFields,
     cached_size: ::protobuf::CachedSize,
 }
 
@@ -838,7 +838,7 @@ pub struct Mixin {
     pub name: ::std::string::String,
     pub root: ::std::string::String,
     // special fields
-    unknown_fields: ::protobuf::UnknownFields,
+    pub unknown_fields: ::protobuf::UnknownFields,
     cached_size: ::protobuf::CachedSize,
 }
 
diff --git a/protobuf/src/well_known_types/duration.rs b/protobuf/src/well_known_types/duration.rs
index e5710242e..c960ad902 100644
--- a/protobuf/src/well_known_types/duration.rs
+++ b/protobuf/src/well_known_types/duration.rs
@@ -27,7 +27,7 @@ pub struct Duration {
     pub seconds: i64,
     pub nanos: i32,
     // special fields
-    unknown_fields: ::protobuf::UnknownFields,
+    pub unknown_fields: ::protobuf::UnknownFields,
     cached_size: ::protobuf::CachedSize,
 }
 
diff --git a/protobuf/src/well_known_types/empty.rs b/protobuf/src/well_known_types/empty.rs
index b2c4ca3d4..ca9078cfc 100644
--- a/protobuf/src/well_known_types/empty.rs
+++ b/protobuf/src/well_known_types/empty.rs
@@ -24,7 +24,7 @@ use protobuf::ProtobufEnum as ProtobufEnum_imported_for_functions;
 #[derive(PartialEq,Clone,Default)]
 pub struct Empty {
     // special fields
-    unknown_fields: ::protobuf::UnknownFields,
+    pub unknown_fields: ::protobuf::UnknownFields,
     cached_size: ::protobuf::CachedSize,
 }
 
diff --git a/protobuf/src/well_known_types/field_mask.rs b/protobuf/src/well_known_types/field_mask.rs
index e820bcbe1..3a936c212 100644
--- a/protobuf/src/well_known_types/field_mask.rs
+++ b/protobuf/src/well_known_types/field_mask.rs
@@ -26,7 +26,7 @@ pub struct FieldMask {
     // message fields
     pub paths: ::protobuf::RepeatedField<::std::string::String>,
     // special fields
-    unknown_fields: ::protobuf::UnknownFields,
+    pub unknown_fields: ::protobuf::UnknownFields,
     cached_size: ::protobuf::CachedSize,
 }
 
diff --git a/protobuf/src/well_known_types/source_context.rs b/protobuf/src/well_known_types/source_context.rs
index 64825896f..c723a50d5 100644
--- a/protobuf/src/well_known_types/source_context.rs
+++ b/protobuf/src/well_known_types/source_context.rs
@@ -26,7 +26,7 @@ pub struct SourceContext {
     // message fields
     pub file_name: ::std::string::String,
     // special fields
-    unknown_fields: ::protobuf::UnknownFields,
+    pub unknown_fields: ::protobuf::UnknownFields,
     cached_size: ::protobuf::CachedSize,
 }
 
diff --git a/protobuf/src/well_known_types/struct_pb.rs b/protobuf/src/well_known_types/struct_pb.rs
index 78e78af68..66a6e7c9e 100644
--- a/protobuf/src/well_known_types/struct_pb.rs
+++ b/protobuf/src/well_known_types/struct_pb.rs
@@ -26,7 +26,7 @@ pub struct Struct {
     // message fields
     pub fields: ::std::collections::HashMap<::std::string::String, Value>,
     // special fields
-    unknown_fields: ::protobuf::UnknownFields,
+    pub unknown_fields: ::protobuf::UnknownFields,
     cached_size: ::protobuf::CachedSize,
 }
 
@@ -171,7 +171,7 @@ pub struct Value {
     // message oneof groups
     pub kind: ::std::option::Option<Value_oneof_kind>,
     // special fields
-    unknown_fields: ::protobuf::UnknownFields,
+    pub unknown_fields: ::protobuf::UnknownFields,
     cached_size: ::protobuf::CachedSize,
 }
 
@@ -655,7 +655,7 @@ pub struct ListValue {
     // message fields
     pub values: ::protobuf::RepeatedField<Value>,
     // special fields
-    unknown_fields: ::protobuf::UnknownFields,
+    pub unknown_fields: ::protobuf::UnknownFields,
     cached_size: ::protobuf::CachedSize,
 }
 
diff --git a/protobuf/src/well_known_types/timestamp.rs b/protobuf/src/well_known_types/timestamp.rs
index a18ea5f31..87f0279d3 100644
--- a/protobuf/src/well_known_types/timestamp.rs
+++ b/protobuf/src/well_known_types/timestamp.rs
@@ -27,7 +27,7 @@ pub struct Timestamp {
     pub seconds: i64,
     pub nanos: i32,
     // special fields
-    unknown_fields: ::protobuf::UnknownFields,
+    pub unknown_fields: ::protobuf::UnknownFields,
     cached_size: ::protobuf::CachedSize,
 }
 
diff --git a/protobuf/src/well_known_types/type_pb.rs b/protobuf/src/well_known_types/type_pb.rs
index aec89878a..92145e7d6 100644
--- a/protobuf/src/well_known_types/type_pb.rs
+++ b/protobuf/src/well_known_types/type_pb.rs
@@ -31,7 +31,7 @@ pub struct Type {
     pub source_context: ::protobuf::SingularPtrField<::protobuf::well_known_types::SourceContext>,
     pub syntax: Syntax,
     // special fields
-    unknown_fields: ::protobuf::UnknownFields,
+    pub unknown_fields: ::protobuf::UnknownFields,
     cached_size: ::protobuf::CachedSize,
 }
 
@@ -412,7 +412,7 @@ pub struct Field {
     pub json_name: ::std::string::String,
     pub default_value: ::std::string::String,
     // special fields
-    unknown_fields: ::protobuf::UnknownFields,
+    pub unknown_fields: ::protobuf::UnknownFields,
     cached_size: ::protobuf::CachedSize,
 }
 
@@ -1054,7 +1054,7 @@ pub struct Enum {
     pub source_context: ::protobuf::SingularPtrField<::protobuf::well_known_types::SourceContext>,
     pub syntax: Syntax,
     // special fields
-    unknown_fields: ::protobuf::UnknownFields,
+    pub unknown_fields: ::protobuf::UnknownFields,
     cached_size: ::protobuf::CachedSize,
 }
 
@@ -1388,7 +1388,7 @@ pub struct EnumValue {
     pub number: i32,
     pub options: ::protobuf::RepeatedField<Option>,
     // special fields
-    unknown_fields: ::protobuf::UnknownFields,
+    pub unknown_fields: ::protobuf::UnknownFields,
     cached_size: ::protobuf::CachedSize,
 }
 
@@ -1621,7 +1621,7 @@ pub struct Option {
     pub name: ::std::string::String,
     pub value: ::protobuf::SingularPtrField<::protobuf::well_known_types::Any>,
     // special fields
-    unknown_fields: ::protobuf::UnknownFields,
+    pub unknown_fields: ::protobuf::UnknownFields,
     cached_size: ::protobuf::CachedSize,
 }
 
diff --git a/protobuf/src/well_known_types/wrappers.rs b/protobuf/src/well_known_types/wrappers.rs
index 89ebd4a99..261fa918e 100644
--- a/protobuf/src/well_known_types/wrappers.rs
+++ b/protobuf/src/well_known_types/wrappers.rs
@@ -26,7 +26,7 @@ pub struct DoubleValue {
     // message fields
     pub value: f64,
     // special fields
-    unknown_fields: ::protobuf::UnknownFields,
+    pub unknown_fields: ::protobuf::UnknownFields,
     cached_size: ::protobuf::CachedSize,
 }
 
@@ -169,7 +169,7 @@ pub struct FloatValue {
     // message fields
     pub value: f32,
     // special fields
-    unknown_fields: ::protobuf::UnknownFields,
+    pub unknown_fields: ::protobuf::UnknownFields,
     cached_size: ::protobuf::CachedSize,
 }
 
@@ -312,7 +312,7 @@ pub struct Int64Value {
     // message fields
     pub value: i64,
     // special fields
-    unknown_fields: ::protobuf::UnknownFields,
+    pub unknown_fields: ::protobuf::UnknownFields,
     cached_size: ::protobuf::CachedSize,
 }
 
@@ -455,7 +455,7 @@ pub struct UInt64Value {
     // message fields
     pub value: u64,
     // special fields
-    unknown_fields: ::protobuf::UnknownFields,
+    pub unknown_fields: ::protobuf::UnknownFields,
     cached_size: ::protobuf::CachedSize,
 }
 
@@ -598,7 +598,7 @@ pub struct Int32Value {
     // message fields
     pub value: i32,
     // special fields
-    unknown_fields: ::protobuf::UnknownFields,
+    pub unknown_fields: ::protobuf::UnknownFields,
     cached_size: ::protobuf::CachedSize,
 }
 
@@ -741,7 +741,7 @@ pub struct UInt32Value {
     // message fields
     pub value: u32,
     // special fields
-    unknown_fields: ::protobuf::UnknownFields,
+    pub unknown_fields: ::protobuf::UnknownFields,
     cached_size: ::protobuf::CachedSize,
 }
 
@@ -884,7 +884,7 @@ pub struct BoolValue {
     // message fields
     pub value: bool,
     // special fields
-    unknown_fields: ::protobuf::UnknownFields,
+    pub unknown_fields: ::protobuf::UnknownFields,
     cached_size: ::protobuf::CachedSize,
 }
 
@@ -1027,7 +1027,7 @@ pub struct StringValue {
     // message fields
     pub value: ::std::string::String,
     // special fields
-    unknown_fields: ::protobuf::UnknownFields,
+    pub unknown_fields: ::protobuf::UnknownFields,
     cached_size: ::protobuf::CachedSize,
 }
 
@@ -1177,7 +1177,7 @@ pub struct BytesValue {
     // message fields
     pub value: ::std::vec::Vec<u8>,
     // special fields
-    unknown_fields: ::protobuf::UnknownFields,
+    pub unknown_fields: ::protobuf::UnknownFields,
     cached_size: ::protobuf::CachedSize,
 }