diff --git a/test/install_script/nvm_do_install b/test/install_script/nvm_do_install
index 5fb0d27..8b3d1db 100755
--- a/test/install_script/nvm_do_install
+++ b/test/install_script/nvm_do_install
@@ -6,3 +6,13 @@ NVM_ENV=testing \. ../../install.sh
 
 #nvm_do_install is available
 type nvm_do_install > /dev/null 2>&1 || die 'nvm_do_install is not available'
+
+FILE_PATH="$(pwd)/nvm_do_install"
+echo $FILE_PATH
+$(NVM_DIR="${FILE_PATH}" nvm_do_install >/dev/null 2>&1)
+EXIT_CODE=$(echo $?)
+[ "${EXIT_CODE}" = '1' ] || die "nvm_do_install should fail if NVM_DIR is a file: expected 1, got <${EXIT_CODE}>"
+
+ACTUAL="$(NVM_DIR="${FILE_PATH}" nvm_do_install 2>&1)"
+EXPECTED="File \"${FILE_PATH}\" has the same name as installation directory."
+[ "${ACTUAL}" = "${EXPECTED}" ] || die "got <${ACTUAL}>, expected <${EXPECTED}>"