diff --git a/dev/appveyor-install-dependencies.ps1 b/dev/appveyor-install-dependencies.ps1
index 06d9d70af3..cc68ffb90d 100644
--- a/dev/appveyor-install-dependencies.ps1
+++ b/dev/appveyor-install-dependencies.ps1
@@ -116,7 +116,7 @@ Pop-Location
 
 # ========================== R
 $rVer = "3.5.1"
-$rToolsVer = "3.4.0"
+$rToolsVer = "3.5.1"
 
 InstallR
 InstallRtools