diff --git a/.appveyor.yml b/.appveyor.yml
index 52dd4ba..acdf5f3 100644
--- a/.appveyor.yml
+++ b/.appveyor.yml
@@ -24,7 +24,7 @@ install:
     if ($env:PYTHON) {
       if ($env:PLATFORM -eq "x64") { $env:PYTHON = "$env:PYTHON-x64" }
       $env:PATH = "C:\Python$env:PYTHON\;C:\Python$env:PYTHON\Scripts\;$env:PATH"
-      pip install --disable-pip-version-check --user --upgrade pip setuptools six
+      pip install --disable-pip-version-check --user --upgrade pip setuptools six psutil
     } elseif ($env:CONDA) {
       if ($env:CONDA -eq "27") { $env:CONDA = "" }
       if ($env:PLATFORM -eq "x64") { $env:CONDA = "$env:CONDA-x64" }
diff --git a/.travis.yml b/.travis.yml
index 824040d..cb7c2ea 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -114,7 +114,7 @@ install:
   fi
   make -j 4
   $PY -m pip install --upgrade pip
-  travis_wait travis_retry $PIP install scipy six flake8
+  travis_wait travis_retry $PIP install scipy six flake8 psutil
   travis_wait travis_retry $PIP install -r python_bindings/requirements.txt
   travis_retry cd python_bindings && $PY setup.py build install && cd ..