diff --git a/git-portfolio b/git-portfolio
index 5ac74e3..1b62853 100755
--- a/git-portfolio
+++ b/git-portfolio
@@ -1,11 +1,12 @@
 #!/usr/bin/bash
-repos="/tmp/repos-$(cat /dev/urandom | base64 | tr -d '=+/' | head -c 8)"
+N=/dev/null
+repos="/tmp/repos-$(cat /dev/urandom 2>$N | base64 2>$N | tr -d '=+/' 2>$N | head -c 8)"
 if [ -d "$repos" ]; then
 	echo "Error: Temporary directory '$repos' already exists." >&2
 	exit 1
 fi
 mkdir -p "$repos"
-tmp_portfolio="/tmp/portfolio-$(cat /dev/urandom | base64 | tr -d '=+/' | head -c 8)"
+tmp_portfolio="/tmp/portfolio-$(cat /dev/urandom 2>$N | base64 2>$N | tr -d '=+/' 2>$N | head -c 8)"
 if [ -d "$tmp_portfolio" ]; then
 	echo "Error: Temporary directory '$tmp_portfolio' already exists." >&2
 	exit 1