diff --git a/tools/tox_install.sh b/tools/tox_install.sh
index 2fec26fd..12fd57fa 100755
--- a/tools/tox_install.sh
+++ b/tools/tox_install.sh
@@ -55,5 +55,10 @@ fi
 # install will be constrained and we need to unconstrain it.
 edit-constraints $localfile -- $LIB_NAME "-e $LIB_LOCATION"
 
+if [ -z "$@" ]; then
+    echo "No packages to be installed."
+    exit 0
+fi
+
 $install_cmd -U $*
 exit $?