diff --git a/dev/appveyor-install-dependencies.ps1 b/dev/appveyor-install-dependencies.ps1
index e344a7fc23191..3e570a8e98a6f 100644
--- a/dev/appveyor-install-dependencies.ps1
+++ b/dev/appveyor-install-dependencies.ps1
@@ -19,7 +19,7 @@ $CRAN = "https://cloud.r-project.org"
 
 Function InstallR {
   if ( -not(Test-Path Env:\R_ARCH) ) {
-    $arch = "i386"
+    $arch = "x64"
   }
   Else {
     $arch = $env:R_ARCH