sympyを1.1.1から1.3に

pip install --upgrade sympy

でupgradeしようとしたら、その時に古いVersionのSympyがimportされていたためか、

Installing collected packages: sympy
  Found existing installation: sympy 1.1.1
Cannot uninstall 'sympy'. It is a distutils installed project and thus we cannot accurately determine which files belong to it which would lead to only a partia l uninstall.

というメッセージが出て、versionは1.1.1のままでした。その後、開いているJupyterNotebookを全て閉じてupgradeしなおしましたが、下記のようにやはりCannot uninstall 'sympy'が出ます。
どのように対処すればよいかヘルプお願いいたします。

C:\Users\Y-user>pip install --upgrade sympy
Collecting sympy
Requirement already satisfied, skipping upgrade: mpmath>=0.19 in c:\users\y-user
\anaconda3\lib\site-packages (from sympy) (1.0.0)
Installing collected packages: sympy
  Found existing installation: sympy 1.1.1
Cannot uninstall 'sympy'. It is a distutils installed project and thus we cannot
 accurately determine which files belong to it which would lead to only a partia
l uninstall.