diff --git a/GamesDat/Telemetry/Sources/Formula1/F12025/MarshalZone.cs b/GamesDat/Telemetry/Sources/Formula1/F12025/MarshalZone.cs
index 03d4d43..06dd4dc 100644
--- a/GamesDat/Telemetry/Sources/Formula1/F12025/MarshalZone.cs
+++ b/GamesDat/Telemetry/Sources/Formula1/F12025/MarshalZone.cs
@@ -6,6 +6,6 @@ namespace GamesDat.Core.Telemetry.Sources.Formula1.F12025
     public struct MarshalZone
     {
         public float m_zoneStart;    // Fraction (0..1) of way through the lap the marshal zone starts
-        public byte m_zoneFlag;      // -1 = invalid/unknown, 0 = none, 1 = green, 2 = blue, 3 = yellow, 4 = red
+        public sbyte m_zoneFlag;     // -1 = invalid/unknown, 0 = none, 1 = green, 2 = blue, 3 = yellow, 4 = red
     }
 }