diff --git a/lib/package-envs.js b/lib/package-envs.js
index 6b538e5..aa935b2 100644
--- a/lib/package-envs.js
+++ b/lib/package-envs.js
@@ -1,8 +1,14 @@
 // https://github.com/npm/rfcs/pull/183
 
-const envVal = val => Array.isArray(val) ? val.map(v => envVal(v)).join('\n\n')
-  : val === null || val === false ? ''
-  : String(val)
+const envVal = val => {
+  if (Array.isArray(val)) {
+    return val.map(v => envVal(v)).join('\n\n')
+  }
+  if (val === null || val === false) {
+    return ''
+  }
+  return String(val)
+}
 
 const packageEnvs = (env, vals, prefix) => {
   for (const [key, val] of Object.entries(vals)) {