diff --git a/src/config.js b/src/config.js
index 9477555..0f7cf65 100644
--- a/src/config.js
+++ b/src/config.js
@@ -13,7 +13,7 @@ export const DEBUG = false;
 // walls) as simple colored rectangles that track the chassis, plus a live
 // per-kid local-position/state readout in the PlayScene HUD. Troubleshooting
 // aid for ejection behavior - off during normal play.
-export const COMPARTMENT_DEBUG = true;
+export const COMPARTMENT_DEBUG = false;
 
 export const STORAGE_KEY = 'monsterplex.progress.v1';
 
diff --git a/src/systems/KidManager.js b/src/systems/KidManager.js
index 8de5c73..ec16bd0 100644
--- a/src/systems/KidManager.js
+++ b/src/systems/KidManager.js
@@ -162,21 +162,45 @@ export default class KidManager {
   // technique as Bus.js's wheel clamp). Never clamps the top - that's the
   // one side deliberately left open (the compartment has no ceiling, see
   // Bus.js/_buildCompartment and config.js).
+  //
+  // Only a kid actually within the compartment's horizontal span is
+  // clamped at all - the radius pre-check below (distance to the chassis
+  // center) alone can't tell "just tunneled through the floor" apart from
+  // "resting on the ground somewhere else in the level at roughly the
+  // bus's height": the chassis floats ~a chassis-height above the ground,
+  // so a kid sitting on nearby ground ends up with localY BELOW the floor
+  // line and would be yanked up into the bus every tick until the bus
+  // drove out of compartmentClampRadius (the "ejected kid teleported to
+  // the bus" bug). A kid that tunneled through the floor/wall is, by
+  // definition, inside the span when it crossed it, so bounding BOTH axes
+  // keeps the tunnel guard working while leaving outside kids alone.
   _clampToCompartment(kid, chassis, cos, sin) {
     const dx = kid.image.x - chassis.x;
     const dy = kid.image.y - chassis.y;
 
     // A kid genuinely outside compartmentClampRadius was never inside the
-    // compartment this tick - skip it entirely, rather than let the below
-    // checks (which only bound ONE axis each) treat "far away in the other
-    // axis" as a boundary violation. Without this, a kid resting anywhere
-    // else in the level could get yanked toward wherever the bus currently
-    // is, since local-frame coordinates alone don't distinguish "just
-    // tunneled through" from "elsewhere entirely."
+    // compartment this tick - a cheap early-out that also bounds the
+    // span check below (a local-frame coordinate alone can't tell "far
+    // away in the other axis" apart from "at the boundary", so the radius
+    // check is still needed even with the span bound).
     if (dx * dx + dy * dy > BUS.compartmentClampRadius * BUS.compartmentClampRadius) return;
 
     let localX = dx * cos + dy * sin;
     let localY = -dx * sin + dy * cos;
+
+    // The actual span guard: a kid is only clamped while its circle can
+    // still overlap a compartment fixture - the floor reaches
+    // +/-compartmentHalfWidth, the walls out to
+    // +/-compartmentHalfWidth + wallThickness/2 - expanded by the kid's
+    // radius, beyond which it overlaps neither and so has nothing to
+    // tunnel back out of. A kid that tunneled through the floor/wall is,
+    // by definition, inside that extent when it crossed it, so the tunnel
+    // guard keeps working while a kid resting on the ground outside the
+    // bus (localY below the floor line but |localX| past this) is left
+    // alone instead of yanked up into the bus every tick.
+    const spanExtent = BUS.compartmentHalfWidth + BUS.compartmentWallThickness / 2 + KID.radius;
+    if (Math.abs(localX) > spanExtent) return;
+
     let hitFloor = false;
     let hitLeftWall = false;
     let hitRightWall = false;