diff --git a/src/NmeaParser.Tests/BufferedStringDevice.cs b/src/NmeaParser.Tests/BufferedStringDevice.cs
index e8e61f5..af41900 100644
--- a/src/NmeaParser.Tests/BufferedStringDevice.cs
+++ b/src/NmeaParser.Tests/BufferedStringDevice.cs
@@ -9,7 +9,7 @@ namespace NmeaParser.Tests
 	internal class BufferedStringDevice : NmeaParser.BufferedStreamDevice
 	{
 		string m_data;
-		public BufferedStringDevice(string data)
+		public BufferedStringDevice(string data) : base(1)
 		{
 			m_data = data;
 		}