diff --git a/Sources/TSFCASFileTree/BinarySearch.swift b/Sources/TSFCASFileTree/BinarySearch.swift
index 91c61b3..083abcb 100644
--- a/Sources/TSFCASFileTree/BinarySearch.swift
+++ b/Sources/TSFCASFileTree/BinarySearch.swift
@@ -12,6 +12,7 @@ extension LLBCASFileTree {
     public static func binarySearch<C: RandomAccessCollection>(
         _ elements: C, _ compare: (C.Element) -> Int
     ) -> C.Index? {
+        guard !elements.isEmpty else { return nil }
         var lo: C.Index = elements.startIndex
         var hi: C.Index = elements.index(before: elements.endIndex)