diff --git a/OpenRA.Mods.Common/UtilityCommands/UpgradeRules.cs b/OpenRA.Mods.Common/UtilityCommands/UpgradeRules.cs
index 688b0680f2..6db88ddb75 100644
--- a/OpenRA.Mods.Common/UtilityCommands/UpgradeRules.cs
+++ b/OpenRA.Mods.Common/UtilityCommands/UpgradeRules.cs
@@ -2253,6 +2253,19 @@ namespace OpenRA.Mods.Common.UtilityCommands
 					}
 				}
 
+				// ChargeTime is now replaced by ChargeDelay.
+				// ChargeDelay uses 500 as a default now.
+				if (engineVersion < 20151022)
+				{
+					if (depth == 2 && parentKey == "PortableChrono" && node.Key == "ChargeTime")
+					{
+						node.Key = "ChargeDelay";
+
+						if (node.Value.Value != null)
+							node.Value.Value = (Exts.ParseIntegerInvariant(node.Value.Value) * 25).ToString();
+					}
+				}
+
 				UpgradeActorRules(engineVersion, ref node.Value.Nodes, node, depth + 1);
 			}
 		}
diff --git a/OpenRA.Mods.RA/Traits/PortableChrono.cs b/OpenRA.Mods.RA/Traits/PortableChrono.cs
index d25c5a1e13..e6babe13db 100644
--- a/OpenRA.Mods.RA/Traits/PortableChrono.cs
+++ b/OpenRA.Mods.RA/Traits/PortableChrono.cs
@@ -20,8 +20,8 @@ namespace OpenRA.Mods.RA.Traits
 {
 	class PortableChronoInfo : ITraitInfo
 	{
-		[Desc("Cooldown in seconds until the unit can teleport.")]
-		public readonly int ChargeTime = 20;
+		[Desc("Cooldown in ticks until the unit can teleport.")]
+		public readonly int ChargeDelay = 500;
 
 		[Desc("Can the unit teleport only a certain distance?")]
 		public readonly bool HasDistanceLimit = true;
@@ -97,7 +97,7 @@ namespace OpenRA.Mods.RA.Traits
 
 		public void ResetChargeTime()
 		{
-			chargeTick = 25 * Info.ChargeTime;
+			chargeTick = Info.ChargeDelay;
 		}
 
 		public bool CanTeleport
@@ -107,7 +107,7 @@ namespace OpenRA.Mods.RA.Traits
 
 		public float GetValue()
 		{
-			return (float)((chargeTick - (25 * Info.ChargeTime)) * (Info.ChargeTime * -0.0001));
+			return (float)(Info.ChargeDelay - chargeTick) / Info.ChargeDelay;
 		}
 
 		public Color GetColor() { return Color.Magenta; }