diff --git a/src/OpenLR/Codecs/Binary/Codecs/PointAlongLineLocationCodec.cs b/src/OpenLR/Codecs/Binary/Codecs/PointAlongLineLocationCodec.cs
index 5747036..5fdb68e 100644
--- a/src/OpenLR/Codecs/Binary/Codecs/PointAlongLineLocationCodec.cs
+++ b/src/OpenLR/Codecs/Binary/Codecs/PointAlongLineLocationCodec.cs
@@ -113,6 +113,7 @@ public static byte[] Encode(PointAlongLineLocation location)
             SideOfRoadConverter.Encode(location.SideOfRoad.Value, data, 14, 0);
             if (location.PositiveOffsetPercentage.HasValue)
             { // positive offset percentage is present.
+                OffsetConvertor.EncodeFlag(true, data, 15, 1);
                 OffsetConvertor.Encode(location.PositiveOffsetPercentage.Value, data, 16);
             }