diff --git a/src/sectorBuilder.ts b/src/sectorBuilder.ts
index bf6e3ed..5a37e9f 100644
--- a/src/sectorBuilder.ts
+++ b/src/sectorBuilder.ts
@@ -66,7 +66,9 @@ export class SectorBuilder {
             this.insetDistance
           )
         : undefined;
-      const hasInnerFillPath = Boolean(innerFillPath);
+      const normalizedInnerFillPath =
+        innerFillPath && innerFillPath.length > 0 ? innerFillPath : undefined;
+      const hasInnerFillPath = Boolean(normalizedInnerFillPath);
       const baseFillColor = hasInnerFillPath ? '#ffffff' : fillColor;
 
       const sectorKey = `L${layerIndex}-P${i}`;
@@ -120,7 +122,7 @@ export class SectorBuilder {
         textColor,
         label: isMultiText ? '' : rawContent,
         path: annularSectorPath(layer.rInner, layer.rOuter, aStart, aEnd),
-        innerFillPath,
+        innerFillPath: normalizedInnerFillPath,
         innerFillColor: hasInnerFillPath ? fillColor : undefined,
         textPath,
         textPathId,