1 files changed, 8 insertions, 1 deletions
diff --git a/csharp/src/Google.Protobuf/JsonParser.cs b/csharp/src/Google.Protobuf/JsonParser.cs
index 25afd0f2..10b05362 100644
--- a/csharp/src/Google.Protobuf/JsonParser.cs
+++ b/csharp/src/Google.Protobuf/JsonParser.cs
@@ -647,7 +647,14 @@ namespace Google.Protobuf
                 case FieldType.String:
                     return text;
                 case FieldType.Bytes:
-                    return ByteString.FromBase64(text);
+                    try
+                    {
+                        return ByteString.FromBase64(text);
+                    }
+                    catch (FormatException e)
+                    {
+                        throw InvalidProtocolBufferException.InvalidBase64(e);
+                    }
                 case FieldType.Int32:
                 case FieldType.SInt32:
                 case FieldType.SFixed32: