diff --git a/lib/readerat/readerat.go b/lib/readerat/readerat.go
index ffd96cc..ef819f7 100644
--- a/lib/readerat/readerat.go
+++ b/lib/readerat/readerat.go
@@ -87,7 +87,7 @@
 		return 0, errSeekToInvalidWhence
 	}
 
-	if r.offset < 0 {
+	if offset < 0 {
 		return 0, errSeekToNegativePosition
 	}
 	r.offset = offset