diff --git a/Installer/pkgPostInstall.sh b/Installer/pkgPostInstall.sh
index 8e8df3ae..adbb0cff 100644
--- a/Installer/pkgPostInstall.sh
+++ b/Installer/pkgPostInstall.sh
@@ -3,18 +3,22 @@
 TARGET='vChewing'
 login_user=$(/usr/bin/stat -f%Su /dev/console)
 
-# First, copy the wrongfully installed contents to the right location:
-cp -r /Library/Input\ Methods/"${TARGET}".app /Users/"${login_user}"/Library/Input\ Methods/ || true
-cp -r /Library/Keyboard\ Layouts/"${TARGET}"* /Users/"${login_user}"/Library/Keyboard\ Layouts/ || true
-chown "${login_user}" /Users/"${login_user}"/Library/Input\ Methods/"${TARGET}".app || true
-chown "${login_user}" /Users/"${login_user}"/Library/Keyboard\ Layouts/"${TARGET}"* || true
+base_ver=12.0
+ver=$(sw_vers | grep ProductVersion | cut -d':' -f2 | tr -d ' ')
+if [ $(echo -e $base_ver"\n"$ver | sort -V | tail -1) == "$base_ver" ]
+then
+  # Copy the wrongfully installed contents to the right location:
+  cp -r /Library/Input\ Methods/"${TARGET}".app /Users/"${login_user}"/Library/Input\ Methods/ || true
+  cp -r /Library/Keyboard\ Layouts/"${TARGET}"* /Users/"${login_user}"/Library/Keyboard\ Layouts/ || true
 
-sleep 1
-
-# Second, clean the wrongfully installed contents:
-rm -rf /Library/Input\ Methods/"${TARGET}".app || true
-rm -rf /Library/Keyboard\ Layouts/"${TARGET}"* || true
-sleep 1
+  # Clean the wrongfully installed contents:
+  chown "${login_user}" /Users/"${login_user}"/Library/Input\ Methods/"${TARGET}".app || true
+  chown "${login_user}" /Users/"${login_user}"/Library/Keyboard\ Layouts/"${TARGET}"* || true
+  sleep 1
+  rm -rf /Library/Input\ Methods/"${TARGET}".app || true
+  rm -rf /Library/Keyboard\ Layouts/"${TARGET}"* || true
+  sleep 1
+fi
 
 # Finally, register the input method:
 /Users/"${login_user}"/Library/Input\ Methods/"${TARGET}".app/Contents/MacOS/"${TARGET}" install --all || true