diff --git a/nvm.sh b/nvm.sh
index 24ff367..e2ce05d 100644
--- a/nvm.sh
+++ b/nvm.sh
@@ -557,18 +557,20 @@ nvm_ls() {
     if [ -z "$PATTERN" ]; then
       PATTERN='v'
     fi
-    VERSIONS="$(command find $NVM_DIRS_TO_SEARCH -maxdepth 1 -type d -name "$PATTERN*" \
-      | command sed "s#$NVM_VERSION_DIR_IOJS/#"$NVM_IOJS_PREFIX"-#" \
-      | command grep -v "$NVM_VERSION_DIR_IOJS" \
-      | command sed "s#^$NVM_DIR/##" \
-      | command grep -v -e '^versions$' \
-      | command sed 's#^versions/##' \
-      | sed -e "s/^v/$NVM_NODE_PREFIX-v/" \
-      | sed -e "s#^\($NVM_IOJS_PREFIX\)[-/]v#\1.v#" | sed -e "s#^\($NVM_NODE_PREFIX\)[-/]v#\1.v#" \
-      | command sort -t. -u -k 2.2,2n -k 3,3n -k 4,4n \
-      | command sort -s -t- -k1.1,1.1 \
-      | command sed "s/^\($NVM_IOJS_PREFIX\)\./\1-/" \
-      | command sed "s/^$NVM_NODE_PREFIX\.//")"
+    if [ -n "$NVM_DIRS_TO_SEARCH" ]; then
+      VERSIONS="$(command find $NVM_DIRS_TO_SEARCH -maxdepth 1 -type d -name "$PATTERN*" \
+        | command sed "s#$NVM_VERSION_DIR_IOJS/#"$NVM_IOJS_PREFIX"-#" \
+        | command grep -v "$NVM_VERSION_DIR_IOJS" \
+        | command sed "s#^$NVM_DIR/##" \
+        | command grep -v -e '^versions$' \
+        | command sed 's#^versions/##' \
+        | sed -e "s/^v/$NVM_NODE_PREFIX-v/" \
+        | sed -e "s#^\($NVM_IOJS_PREFIX\)[-/]v#\1.v#" | sed -e "s#^\($NVM_NODE_PREFIX\)[-/]v#\1.v#" \
+        | command sort -t. -u -k 2.2,2n -k 3,3n -k 4,4n \
+        | command sort -s -t- -k1.1,1.1 \
+        | command sed "s/^\($NVM_IOJS_PREFIX\)\./\1-/" \
+        | command sed "s/^$NVM_NODE_PREFIX\.//")"
+    fi
 
     if [ $ZHS_HAS_SHWORDSPLIT_UNSET -eq 1 ] && nvm_has "unsetopt"; then
       unsetopt shwordsplit