diff --git a/components/SlideToConfirm.tsx b/components/SlideToConfirm.tsx
index 9cdeb50..9aa496d 100644
--- a/components/SlideToConfirm.tsx
+++ b/components/SlideToConfirm.tsx
@@ -45,8 +45,10 @@ export function SlideToConfirm({ label = 'Slide to confirm', color = '#059669',
   ).current;
 
   // Interpolate opacity of the label as handle moves right
+  // Guard: inputRange must be monotonically non-decreasing (maxX could be 0 before layout)
+  const safeMax = Math.max(maxX * 0.5, 1);
   const labelOpacity = pan.interpolate({
-    inputRange: [0, maxX * 0.5],
+    inputRange: [0, safeMax],
     outputRange: [1, 0],
     extrapolate: 'clamp',
   });