diff --git a/src/app/alignment-ui.ts b/src/app/alignment-ui.ts
index e891ce2..dd5d437 100644
--- a/src/app/alignment-ui.ts
+++ b/src/app/alignment-ui.ts
@@ -63,6 +63,8 @@ export function mountAlignment(deps: AlignmentDeps): void {
   overlay.addEventListener('mousedown', (ev) => {
     const H = deps.getHomography();
     if (!H) return;
+    // Another module (e.g. calibration) has armed the overlay for this click; don't hijack it.
+    if (!armOrigin && overlay.classList.contains('interactive')) return;
     if (armOrigin) {
       const a = deps.getAlignment();
       const m = imageToMachine(H, normFromEvent(overlay, ev));
@@ -98,11 +100,13 @@ export function mountAlignment(deps: AlignmentDeps): void {
   });
 
   window.addEventListener('mouseup', () => {
+    if (!dragging) return; // only release the overlay if THIS module was dragging
     dragging = false;
     overlay.classList.remove('interactive');
   });
 
   window.addEventListener('keydown', (ev) => {
+    if (document.activeElement instanceof HTMLInputElement) return;
     const a = deps.getAlignment();
     const step = 1;
     if (ev.key === 'ArrowLeft') a.tx -= step;