diff --git a/backend/sftp/sftp.go b/backend/sftp/sftp.go
index 38acd3ad8..8e4eb905e 100644
--- a/backend/sftp/sftp.go
+++ b/backend/sftp/sftp.go
@@ -1,6 +1,6 @@
 // Package sftp provides a filesystem interface using github.com/pkg/sftp
 
-// +build !plan9,go1.8
+// +build !plan9,go1.9
 
 package sftp
 
diff --git a/backend/sftp/sftp_internal_test.go b/backend/sftp/sftp_internal_test.go
index 80a75b8e9..ad99ff7d2 100644
--- a/backend/sftp/sftp_internal_test.go
+++ b/backend/sftp/sftp_internal_test.go
@@ -1,4 +1,4 @@
-// +build !plan9,go1.8
+// +build !plan9,go1.9
 
 package sftp
 
diff --git a/backend/sftp/sftp_test.go b/backend/sftp/sftp_test.go
index 824d99bc6..10d7376b2 100644
--- a/backend/sftp/sftp_test.go
+++ b/backend/sftp/sftp_test.go
@@ -1,6 +1,6 @@
 // Test Sftp filesystem interface
 
-// +build !plan9,go1.8
+// +build !plan9,go1.9
 
 package sftp_test
 
diff --git a/backend/sftp/sftp_unsupported.go b/backend/sftp/sftp_unsupported.go
index e3d09e48e..e9ecd15b0 100644
--- a/backend/sftp/sftp_unsupported.go
+++ b/backend/sftp/sftp_unsupported.go
@@ -1,6 +1,6 @@
 // Build for sftp for unsupported platforms to stop go complaining
 // about "no buildable Go source files "
 
-// +build plan9 !go1.8
+// +build plan9 !go1.9
 
 package sftp
diff --git a/backend/sftp/stringlock.go b/backend/sftp/stringlock.go
index 157ee362b..a1bfab41e 100644
--- a/backend/sftp/stringlock.go
+++ b/backend/sftp/stringlock.go
@@ -1,4 +1,4 @@
-// +build !plan9,go1.8
+// +build !plan9,go1.9
 
 package sftp
 
diff --git a/backend/sftp/stringlock_test.go b/backend/sftp/stringlock_test.go
index 9c129c343..6e368f45a 100644
--- a/backend/sftp/stringlock_test.go
+++ b/backend/sftp/stringlock_test.go
@@ -1,4 +1,4 @@
-// +build !plan9,go1.8
+// +build !plan9,go1.9
 
 package sftp