diff --git a/bin/yarn b/bin/yarn
index 64fc973da7..89b05ba594 100755
--- a/bin/yarn
+++ b/bin/yarn
@@ -1,11 +1,11 @@
 #!/bin/sh
 basedir=$(dirname "$(readlink "$0" || echo "$(echo "$0" | sed -e 's,\\,/,g')")")
 
-is_msys=0
+use_winpty=0
 
 case `uname` in
   *CYGWIN*) basedir=`cygpath -w "$basedir"`;;
-  *MSYS_NT*) is_msys=1;;
+  MSYS*|MINGW*) use_winpty=1;;
 esac
 
 command_exists() {
@@ -13,7 +13,7 @@ command_exists() {
 }
 
 if command_exists node; then
-  if [ $is_msys -eq 1 ]; then
+  if [ $use_winpty -eq 1 ]; then
     winpty node "$basedir/yarn.js" "$@"
   else
     node "$basedir/yarn.js" "$@"