diff --git a/src/app.js b/src/app.js
index 02afc46..69ad9b1 100644
--- a/src/app.js
+++ b/src/app.js
@@ -239,6 +239,13 @@ function attachEdgeTabsToNearestBusbars(busbars, geometries, positions, options)
     }
 
     for (const best of selectedByBusbar) {
+        // Skip if the anchor is too far horizontally from the tab centre — this
+        // means the busbar doesn't straddle the slot and the arm would require a
+        // hard 90° bend (e.g. a single-column vertical busbar next to a tab).
+        // Valid connections have an edge midpoint exactly at tab.x → deltaX ≈ 0.
+        // Invalid single-column case has deltaX ≈ ±pitch/2 > cellRadius.
+        if (Math.abs(best.deltaX) > cellRadius) continue;
+
         const sameTabCandidates = conflictsByTab.get(best.tabKey) || [];
         const leftCandidate = sameTabCandidates.find((candidate) => candidate.deltaX < -betweenBusbarThreshold);
         const rightCandidate = sameTabCandidates.find((candidate) => candidate.deltaX > betweenBusbarThreshold);
diff --git a/src/busbar-geometry.js b/src/busbar-geometry.js
index d49fa91..c67fde0 100644
--- a/src/busbar-geometry.js
+++ b/src/busbar-geometry.js
@@ -309,18 +309,12 @@ function computeEdgeOverlapFeatures(cellIndices, positions, layoutType, overlapL
         return { extraPads: [], extraSegments: [] };
     }
 
-    // Skip overlap if it would create a hard 90° bend at every boundary cell.
-    // This happens when no boundary cell has any busbar neighbour in the same row
-    // (i.e. the busbar only spans one column and all its internal connections are
-    // vertical).  In that case the horizontal arm is perpendicular to every
-    // connection and would overlap adjacent busbars.
-    const hasSameRowBusbarNeighbour = boundaryEntries.some((entry) =>
-        selected.some((other) =>
-            other.index !== entry.index &&
-            Math.abs(other.pos[1] - entry.pos[1]) <= yTolerance
-        )
-    );
-    if (!hasSameRowBusbarNeighbour) {
+    // Skip overlap if the busbar spans only one column (all cells share the same
+    // X-coordinate, rounded to 0.1 mm).  A single-column busbar's internal edges
+    // are all vertical, so a horizontal arm would be at 90° to every connection
+    // and would visually overlap adjacent busbars.
+    const uniqueXCount = new Set(selected.map(e => Math.round(e.pos[0] * 10))).size;
+    if (uniqueXCount < 2) {
         return { extraPads: [], extraSegments: [] };
     }