diff --git a/tools/travis_install_optional.sh b/tools/travis_install_optional.sh
index 9ecb9d20..ec01d899 100755
--- a/tools/travis_install_optional.sh
+++ b/tools/travis_install_optional.sh
@@ -9,26 +9,26 @@ if [[ $TRAVIS_PYTHON_VERSION == 2.7* ]]; then
 
 else
     sudo apt-get install -q libqt4-dev
-    pip install PySide $WHEELHOUSE
+    pip install -q PySide $WHEELHOUSE
     python ~/virtualenv/python${TRAVIS_PYTHON_VERSION}/bin/pyside_postinstall.py -install
 fi
 
 # imread does NOT support py3.2
 if [[ $TRAVIS_PYTHON_VERSION != 3.2 ]]; then
     sudo apt-get install -q libtiff4-dev libwebp-dev libpng12-dev xcftools
-    pip install imread
+    pip install -q imread
 fi
 
 # TODO: update when SimpleITK become available on py34 or hopefully pip
 if [[ $TRAVIS_PYTHON_VERSION != 3.4 ]]; then
-    easy_install SimpleITK
+    easy_install -q SimpleITK
 fi
 
-sudo apt-get install libfreeimage3
-pip install astropy
+sudo apt-get install -q libfreeimage3
+pip install -q astropy
 
 if [[ $TRAVIS_PYTHON_VERSION == 2.* ]]; then
-    pip install pyamg
+    pip install -q pyamg
 fi
 
-pip install tifffile
+pip install -q tifffile