diff --git a/lib/commands/install.js b/lib/commands/install.js
index 24e5f6819b314..383de12174e4f 100644
--- a/lib/commands/install.js
+++ b/lib/commands/install.js
@@ -97,10 +97,9 @@ class Install extends ArboristWorkspaceCmd {
 
   async exec (args) {
     // the /path/to/node_modules/..
-    const globalTop = resolve(this.npm.globalDir, '..')
     const ignoreScripts = this.npm.config.get('ignore-scripts')
     const isGlobalInstall = this.npm.global
-    const where = isGlobalInstall ? globalTop : this.npm.prefix
+    const where = this.npm.prefix
     const forced = this.npm.config.get('force')
     const scriptShell = this.npm.config.get('script-shell') || undefined
 
@@ -128,13 +127,13 @@ class Install extends ArboristWorkspaceCmd {
     args = args.filter(a => resolve(a) !== this.npm.prefix)
 
     // `npm i -g` => "install this package globally"
-    if (where === globalTop && !args.length) {
+    if (isGlobalInstall && !args.length) {
       args = ['.']
     }
 
     // throw usage error if trying to install empty package
     // name to global space, e.g: `npm i -g ""`
-    if (where === globalTop && !args.every(Boolean)) {
+    if (isGlobalInstall && !args.every(Boolean)) {
       throw this.usageError()
     }