diff --git a/addons/sourcemod/scripting/shavit-core.sp b/addons/sourcemod/scripting/shavit-core.sp
index cd91bb1e..98aad5f1 100644
--- a/addons/sourcemod/scripting/shavit-core.sp
+++ b/addons/sourcemod/scripting/shavit-core.sp
@@ -2569,10 +2569,15 @@ bool CanStartTimer(int client, int track, bool skipGroundCheck)
 
 	if (skipGroundTimer) return true;
 
-	int halfSecOfTicks = RoundFloat(0.5 / GetTickInterval());
-	int onGroundTicks = gI_LastTickcount[client] - gI_FirstTouchedGround[client];
+	if (gI_FirstTouchedGround[client] > 0)
+	{
+		int halfSecOfTicks = RoundFloat(0.5 / GetTickInterval());
+		int onGroundTicks = gI_LastTickcount[client] - gI_FirstTouchedGround[client];
 
-	return onGroundTicks >= halfSecOfTicks;
+		return onGroundTicks >= halfSecOfTicks;
+	}
+
+	return false;
 }
 
 void StartTimer(int client, int track, bool skipGroundCheck)
@@ -3672,6 +3677,11 @@ public Action OnPlayerRunCmd(int client, int &buttons, int &impulse, float vel[3
 		}
 	}
 
+	if (!bOnGround)
+	{
+		gI_FirstTouchedGround[client] = 0;
+	}
+
 	// This can be bypassed by spamming +duck on CSS which causes `iGroundEntity` to be `-1` here...
 	//   (e.g. an autobhop + velocity_limit style...)
 	// m_hGroundEntity changes from 0 -> -1 same tick which causes problems and I'm not sure what the best way / place to handle that is...