diff --git a/.travis.yml b/.travis.yml
index 2f896c3..b39b7c4 100755
--- a/.travis.yml
+++ b/.travis.yml
@@ -73,6 +73,7 @@ matrix:
             - graphviz
             - doxygen
             - python3
+            - python3-pip
       script: |
         REPO_DIR=$PWD ;
         mkdir -p $REPO_DIR/build_for_doxygen && cd $REPO_DIR/build_for_doxygen ;
@@ -80,7 +81,6 @@ matrix:
         $CMAKE_BIN .. -DCMAKE_BUILD_TYPE=RelWithDebInfo -DLIBCOPP_FCONTEXT_USE_TSX=ON -DPROJECT_ENABLE_UNITTEST=ON -DPROJECT_ENABLE_SAMPLE=ON ;
         cd "$REPO_DIR/docs";
         export PATH="$HOME/.local/bin:$PATH" ;
-        which pwsh > /dev/null; 2>&1;
         python3 -m pip install --user --upgrade pip;
         python3 -m pip install --user --upgrade -r requirements.txt;
         if [[ "doxygen" != "$DOXYGEN_BIN" ]] && [[ ! -e "$DOXYGEN_BIN" ]]; then