diff --git a/src/pkg/io/multi.go b/src/pkg/io/multi.go
index 2c7e816..ab8dd5d 100644
--- a/src/pkg/io/multi.go
+++ b/src/pkg/io/multi.go
@@ -26,7 +26,8 @@
 
 // MultiReader returns a Reader that's the logical concatenation of
 // the provided input readers.  They're read sequentially.  Once all
-// inputs are drained, Read will return EOF.
+// inputs have returned EOF, Read will return EOF.  If any of the readers
+// return a non-nil, non-EOF error, Read will return that error.
 func MultiReader(readers ...Reader) Reader {
 	return &multiReader{readers}
 }