diff --git a/lib/reader.js b/lib/reader.js
index 43e78d9d..12d4c0da 100644
--- a/lib/reader.js
+++ b/lib/reader.js
@@ -201,11 +201,15 @@ class ParquetEnvelopeReader {
   }
 
   constructor(readFn, closeFn, fileSize) {
-    this.read = readFn;
+    this.readFn = readFn;
     this.close = closeFn;
     this.fileSize = fileSize;
   }
 
+  async read(offset, length) {
+    return this.readFn(offset, length);
+  }
+
   async readHeader() {
     let buf = await this.read(0, PARQUET_MAGIC.length);