diff --git a/index.js b/index.js
index 3a11fd7..5116431 100644
--- a/index.js
+++ b/index.js
@@ -458,13 +458,13 @@ class Fuse extends Nanoresource {
 
   _op_read (signal, path, fd, buf, len, offsetLow, offsetHigh) {
     this.ops.read(path, fd, buf, len, getDoubleArg(offsetLow, offsetHigh), (err, bytesRead) => {
-      return signal(err, bytesRead, buf.buffer)
+      return signal(err, bytesRead || 0, buf.buffer)
     })
   }
 
   _op_write (signal, path, fd, buf, len, offsetLow, offsetHigh) {
     this.ops.write(path, fd, buf, len, getDoubleArg(offsetLow, offsetHigh), (err, bytesWritten) => {
-      return signal(err, bytesWritten, buf.buffer)
+      return signal(err, bytesWritten || 0, buf.buffer)
     })
   }