diff --git a/src/mode/cam/ops.js b/src/mode/cam/ops.js
index b0e6a3d0..129dc25f 100644
--- a/src/mode/cam/ops.js
+++ b/src/mode/cam/ops.js
@@ -159,7 +159,7 @@
             indices.shift();
             if (op.flats) {
                 let flats = Object.keys(slicer.zFlat)
-                    .map(v => parseFloat(v).round(4))
+                    .map(v => parseFloat(v).round(5))
                     .filter(v => v >= zBottom);
                 flats.forEach(v => {
                     if (!indices.contains(v)) {