diff --git a/src/Protobuf.System.Text.Json/FieldTypeResolver.cs b/src/Protobuf.System.Text.Json/FieldTypeResolver.cs
index c0f70fc..d55b13e 100644
--- a/src/Protobuf.System.Text.Json/FieldTypeResolver.cs
+++ b/src/Protobuf.System.Text.Json/FieldTypeResolver.cs
@@ -1,3 +1,4 @@
+using Google.Protobuf;
 using Google.Protobuf.Reflection;
 using Google.Protobuf.WellKnownTypes;
 using Type = System.Type;
@@ -32,6 +33,8 @@ public static Type ResolverFieldType(FieldDescriptor fieldDescriptor, Dictionary
                 return typeof(bool);
             case FieldType.String:
                 return typeof(string);
+            case FieldType.Bytes:
+                return typeof(ByteString);
             case FieldType.Message when fieldDescriptor.MessageType.ClrType is { } clrType:
                 if (clrType == typeof(DoubleValue))
                     return typeof(double?);
@@ -58,7 +61,7 @@ public static Type ResolverFieldType(FieldDescriptor fieldDescriptor, Dictionary
                 return propertyTypeLookup[fieldDescriptor.PropertyName];
             default:
                 throw new ArgumentOutOfRangeException(nameof(fieldDescriptor),
-                    $"FieldType: '{fieldDescriptor}' is not supported.");
+                    $"FieldType: '{fieldDescriptor.FieldType}' is not supported.");
         }
     }
 }
\ No newline at end of file
diff --git a/src/Protobuf.System.Text.Json/JsonSerializerOptionsExtensions.cs b/src/Protobuf.System.Text.Json/JsonSerializerOptionsExtensions.cs
index c36b0c4..fec419c 100644
--- a/src/Protobuf.System.Text.Json/JsonSerializerOptionsExtensions.cs
+++ b/src/Protobuf.System.Text.Json/JsonSerializerOptionsExtensions.cs
@@ -23,6 +23,7 @@ public static void AddProtobufSupport(this JsonSerializerOptions options, Action
         {
             options.Converters.Add(new TimestampConverter());
         }
+        options.Converters.Add(new ByteStringConverter());
         options.Converters.Add(new ProtobufJsonConverterFactory(jsonProtobufSerializerOptions));
     }
     
diff --git a/src/Protobuf.System.Text.Json/WellKnownTypesConverters/ByteStringConverter.cs b/src/Protobuf.System.Text.Json/WellKnownTypesConverters/ByteStringConverter.cs
new file mode 100644
index 0000000..c3479a9
--- /dev/null
+++ b/src/Protobuf.System.Text.Json/WellKnownTypesConverters/ByteStringConverter.cs
@@ -0,0 +1,26 @@
+using System.Text.Json;
+using System.Text.Json.Serialization;
+using Google.Protobuf;
+
+namespace Protobuf.System.Text.Json.WellKnownTypesConverters;
+
+internal class ByteStringConverter : JsonConverter<ByteString?>
+{
+    public override ByteString? Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
+    {
+        if (reader.GetString() is { } base64String)
+        {
+            return ByteString.FromBase64(base64String);
+        }
+
+        return null;
+    }
+
+    public override void Write(Utf8JsonWriter writer, ByteString? value, JsonSerializerOptions options)
+    {
+        if (value != null)
+        {
+            writer.WriteStringValue(value.ToBase64());
+        }
+    }
+}
\ No newline at end of file
diff --git a/test/Protobuf.System.Text.Json.Tests/DefaultIgnoreConditionTests.Should_not_ignore_default_non_nullable_properties_when_DefaultIgnoreCondition_set_to_WhenWritingNull.approved.json b/test/Protobuf.System.Text.Json.Tests/DefaultIgnoreConditionTests.Should_not_ignore_default_non_nullable_properties_when_DefaultIgnoreCondition_set_to_WhenWritingNull.approved.json
index c263be5..87c6505 100644
--- a/test/Protobuf.System.Text.Json.Tests/DefaultIgnoreConditionTests.Should_not_ignore_default_non_nullable_properties_when_DefaultIgnoreCondition_set_to_WhenWritingNull.approved.json
+++ b/test/Protobuf.System.Text.Json.Tests/DefaultIgnoreConditionTests.Should_not_ignore_default_non_nullable_properties_when_DefaultIgnoreCondition_set_to_WhenWritingNull.approved.json
@@ -12,5 +12,6 @@
   "sfixed32Property": 0,
   "sfixed64Property": 0,
   "boolProperty": false,
-  "stringProperty": ""
+  "stringProperty": "",
+  "bytesProperty": ""
 }
\ No newline at end of file
diff --git a/test/Protobuf.System.Text.Json.Tests/DefaultIgnoreConditionTests.Should_not_ignore_default_properties_when_DefaultIgnoreCondition_set_to_Never.approved.json b/test/Protobuf.System.Text.Json.Tests/DefaultIgnoreConditionTests.Should_not_ignore_default_properties_when_DefaultIgnoreCondition_set_to_Never.approved.json
index c263be5..87c6505 100644
--- a/test/Protobuf.System.Text.Json.Tests/DefaultIgnoreConditionTests.Should_not_ignore_default_properties_when_DefaultIgnoreCondition_set_to_Never.approved.json
+++ b/test/Protobuf.System.Text.Json.Tests/DefaultIgnoreConditionTests.Should_not_ignore_default_properties_when_DefaultIgnoreCondition_set_to_Never.approved.json
@@ -12,5 +12,6 @@
   "sfixed32Property": 0,
   "sfixed64Property": 0,
   "boolProperty": false,
-  "stringProperty": ""
+  "stringProperty": "",
+  "bytesProperty": ""
 }
\ No newline at end of file
diff --git a/test/Protobuf.System.Text.Json.Tests/JsonNamingPolicyTests.Should_ignore_PropertyNamingPolicy_when_UseProtobufJsonNames_set_to_true.approved.json b/test/Protobuf.System.Text.Json.Tests/JsonNamingPolicyTests.Should_ignore_PropertyNamingPolicy_when_UseProtobufJsonNames_set_to_true.approved.json
index 9a88710..1283b7d 100644
--- a/test/Protobuf.System.Text.Json.Tests/JsonNamingPolicyTests.Should_ignore_PropertyNamingPolicy_when_UseProtobufJsonNames_set_to_true.approved.json
+++ b/test/Protobuf.System.Text.Json.Tests/JsonNamingPolicyTests.Should_ignore_PropertyNamingPolicy_when_UseProtobufJsonNames_set_to_true.approved.json
@@ -12,5 +12,6 @@
   "sfixed32Property": 0,
   "sfixed64Property": 0,
   "boolProperty": false,
-  "stringProperty": ""
+  "stringProperty": "",
+  "bytesProperty": ""
 }
\ No newline at end of file
diff --git a/test/Protobuf.System.Text.Json.Tests/JsonNamingPolicyTests.Should_serialize_message_with_primitive_types.approved.json b/test/Protobuf.System.Text.Json.Tests/JsonNamingPolicyTests.Should_serialize_message_with_primitive_types.approved.json
index 488c716..30351d3 100644
--- a/test/Protobuf.System.Text.Json.Tests/JsonNamingPolicyTests.Should_serialize_message_with_primitive_types.approved.json
+++ b/test/Protobuf.System.Text.Json.Tests/JsonNamingPolicyTests.Should_serialize_message_with_primitive_types.approved.json
@@ -12,5 +12,6 @@
   "sfixed32property": 0,
   "sfixed64property": 0,
   "boolproperty": false,
-  "stringproperty": ""
+  "stringproperty": "",
+  "bytesproperty": ""
 }
\ No newline at end of file
diff --git a/test/Protobuf.System.Text.Json.Tests/MessageWithMapsTests.Should_serialize_message_with_map_field.approved.json b/test/Protobuf.System.Text.Json.Tests/MessageWithMapsTests.Should_serialize_message_with_map_field.approved.json
index 34e6706..449aff5 100644
--- a/test/Protobuf.System.Text.Json.Tests/MessageWithMapsTests.Should_serialize_message_with_map_field.approved.json
+++ b/test/Protobuf.System.Text.Json.Tests/MessageWithMapsTests.Should_serialize_message_with_map_field.approved.json
@@ -8,5 +8,8 @@
         "a": 1
       }
     }
+  },
+  "mapStringToBytesType": {
+    "string_key": "YWJj"
   }
 }
\ No newline at end of file
diff --git a/test/Protobuf.System.Text.Json.Tests/MessageWithMapsTests.cs b/test/Protobuf.System.Text.Json.Tests/MessageWithMapsTests.cs
index 04d6ab5..3fbb86b 100644
--- a/test/Protobuf.System.Text.Json.Tests/MessageWithMapsTests.cs
+++ b/test/Protobuf.System.Text.Json.Tests/MessageWithMapsTests.cs
@@ -1,5 +1,6 @@
 using System.Text.Json;
 using System.Text.Json.Protobuf.Tests;
+using Google.Protobuf;
 using Protobuf.System.Text.Json.Tests.Utils;
 using Shouldly;
 using SmartAnalyzers.ApprovalTestsExtensions;
@@ -22,7 +23,8 @@ public void Should_serialize_message_with_map_field()
                 {
                     MapStringToInt = {["a"] = 1}
                 }
-            }
+            },
+            MapStringToBytesType = { ["string_key"] = ByteString.CopyFromUtf8("abc") }
         };
         var jsonSerializerOptions = TestHelper.CreateJsonSerializerOptions();
 
@@ -47,7 +49,8 @@ public void Should_deserialize_message_with_map_field()
                 {
                     MapStringToInt = {["a"] = 1}
                 }
-            }
+            },
+            MapStringToBytesType = { ["string_key"] = ByteString.CopyFromUtf8("abc") }
         };
         var jsonSerializerOptions = TestHelper.CreateJsonSerializerOptions();
 
diff --git a/test/Protobuf.System.Text.Json.Tests/Protos/message_with_maps.proto b/test/Protobuf.System.Text.Json.Tests/Protos/message_with_maps.proto
index 1d42802..a71527d 100644
--- a/test/Protobuf.System.Text.Json.Tests/Protos/message_with_maps.proto
+++ b/test/Protobuf.System.Text.Json.Tests/Protos/message_with_maps.proto
@@ -5,6 +5,7 @@ option csharp_namespace = "System.Text.Json.Protobuf.Tests";
 message MessageWithMaps {
   map<int32, string> map_int_to_string = 1;
   map<string, NestedMessageAsKey> map_string_to_complex_type = 2;
+  map<string, bytes> map_string_to_bytes_type = 3;
 }
 
 message NestedMessageAsKey {
diff --git a/test/Protobuf.System.Text.Json.Tests/Protos/simple_message.proto b/test/Protobuf.System.Text.Json.Tests/Protos/simple_message.proto
index 1719c6c..2805a7e 100644
--- a/test/Protobuf.System.Text.Json.Tests/Protos/simple_message.proto
+++ b/test/Protobuf.System.Text.Json.Tests/Protos/simple_message.proto
@@ -31,6 +31,5 @@ message SimpleMessage {
   
   string string_property = 14;
   
-  // TODO: Support bytes property
-  // bytes bytes_property = 15;
+  bytes bytes_property = 15;
 }
\ No newline at end of file
diff --git a/test/Protobuf.System.Text.Json.Tests/SimpleMessageTests.Should_serialize_message_with_primitive_types.approved.json b/test/Protobuf.System.Text.Json.Tests/SimpleMessageTests.Should_serialize_message_with_primitive_types.approved.json
index b0c1fb0..bab7abd 100644
--- a/test/Protobuf.System.Text.Json.Tests/SimpleMessageTests.Should_serialize_message_with_primitive_types.approved.json
+++ b/test/Protobuf.System.Text.Json.Tests/SimpleMessageTests.Should_serialize_message_with_primitive_types.approved.json
@@ -12,5 +12,6 @@
   "sfixed32Property": 9,
   "sfixed64Property": 10,
   "boolProperty": true,
-  "stringProperty": "hello"
+  "stringProperty": "hello",
+  "bytesProperty": "YWJj"
 }
\ No newline at end of file
diff --git a/test/Protobuf.System.Text.Json.Tests/SimpleMessageTests.cs b/test/Protobuf.System.Text.Json.Tests/SimpleMessageTests.cs
index 2f69e24..6899cf9 100644
--- a/test/Protobuf.System.Text.Json.Tests/SimpleMessageTests.cs
+++ b/test/Protobuf.System.Text.Json.Tests/SimpleMessageTests.cs
@@ -1,5 +1,6 @@
 using System.Text.Json;
 using System.Text.Json.Protobuf.Tests;
+using Google.Protobuf;
 using Protobuf.System.Text.Json.Tests.Utils;
 using Shouldly;
 using SmartAnalyzers.ApprovalTestsExtensions;
@@ -28,9 +29,8 @@ public void Should_serialize_message_with_primitive_types()
             Sfixed32Property = 9,
             Sfixed64Property = 10,
             BoolProperty = true,
-            StringProperty = "hello"
-            // TODO: Support bytes property
-            // BytesProperty = ByteString.CopyFromUtf8("abc")
+            StringProperty = "hello",
+            BytesProperty = ByteString.CopyFromUtf8("abc")
         };
         var jsonSerializerOptions = TestHelper.CreateJsonSerializerOptions();
         
@@ -61,9 +61,8 @@ public void Should_deserialize_message_with_primitive_types()
             Sfixed32Property = 9,
             Sfixed64Property = 10,
             BoolProperty = true,
-            StringProperty = "hello"
-            // TODO: Support bytes property
-            // BytesProperty = ByteString.CopyFromUtf8("abc")
+            StringProperty = "hello",
+            BytesProperty = ByteString.CopyFromUtf8("abc")
         };
         var jsonSerializerOptions = TestHelper.CreateJsonSerializerOptions();