diff --git a/fs.go b/fs.go
index 5e2841c..6026adb 100644
--- a/fs.go
+++ b/fs.go
@@ -1,3 +1,5 @@
+// +build go1.16
+
 package gemini
 
 import (
diff --git a/go.mod b/go.mod
index 3b7df0a..2eb6847 100644
--- a/go.mod
+++ b/go.mod
@@ -1,5 +1,5 @@
 module git.sr.ht/~adnano/go-gemini
 
-go 1.16
+go 1.15
 
 require golang.org/x/net v0.0.0-20210119194325-5f4716e94777