diff --git a/dev/appveyor-install-dependencies.ps1 b/dev/appveyor-install-dependencies.ps1
index e344a7fc23191..fb4cc22de35f4 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
@@ -68,7 +68,7 @@ Function InstallRtools {
     $gccPath = $env:GCC_PATH
   }
   $env:PATH = $RtoolsDrive + '\Rtools40\bin;' + $RtoolsDrive + '\Rtools40\mingw64\bin;' + $RtoolsDrive + '\Rtools40\' + $gccPath + '\bin;' + $env:PATH
-  $env:BINPREF=$RtoolsDrive + '/Rtools40/mingw64/bin/'
+  $env:BINPREF=$RtoolsDrive + '/Rtools40/mingw$(WIN)/bin/'
 }
 
 # create tools directory outside of Spark directory