diff --git a/src/string-section.ts b/src/string-section.ts
index abcacb6..a4d24a2 100644
--- a/src/string-section.ts
+++ b/src/string-section.ts
@@ -38,7 +38,7 @@ export class StringSection {
   }
 
   public startsWith(prefix: string, offset: number = 0) {
-    return this.#parent.startsWith(prefix, this.#offset + offset);
+    return prefix.length <= (this.#length - offset) && this.#parent.startsWith(prefix, this.#offset + offset);
   }
 
   public substring(beginIndex: number = 0, endIndex: number = this.#length - beginIndex) {