diff --git a/nvm.sh b/nvm.sh
index c577cf7..13a30c5 100755
--- a/nvm.sh
+++ b/nvm.sh
@@ -91,8 +91,8 @@ nvm_ls_remote()
         PATTERN=".*"
     fi
     VERSIONS=`curl -s http://nodejs.org/dist/ \
-                  | egrep -o 'v[0-9]+\.[0-9]+\.[0-9]+' \
-                  | grep -w "${PATTERN}" \
+                  | command egrep -o 'v[0-9]+\.[0-9]+\.[0-9]+' \
+                  | command grep -w "${PATTERN}" \
                   | sort -t. -u -k 1.2,1n -k 2,2n -k 3,3n`
     if [ ! "$VERSIONS" ]; then
         echo "N/A"