diff --git a/lib/commands/explain.js b/lib/commands/explain.js
index 1505b4dbf5e9a..5f37ba9925f41 100644
--- a/lib/commands/explain.js
+++ b/lib/commands/explain.js
@@ -92,7 +92,7 @@ class Explain extends ArboristWorkspaceCmd {
     }
 
     // if it's a location, get that node
-    const maybeLoc = arg.replace(/\\/g, '/').replace(/\/+$/, '')
+    const maybeLoc = arg.replace(/\\/g, '/').replace(/(?<!\/)\/+$/, '')
     const nodeByLoc = tree.inventory.get(maybeLoc)
     if (nodeByLoc) {
       return [nodeByLoc]
@@ -100,7 +100,7 @@ class Explain extends ArboristWorkspaceCmd {
 
     // maybe a path to a node_modules folder
     const maybePath = relative(this.npm.prefix, resolve(maybeLoc))
-      .replace(/\\/g, '/').replace(/\/+$/, '')
+      .replace(/\\/g, '/').replace(/(?<!\/)\/+$/, '')
     const nodeByPath = tree.inventory.get(maybePath)
     if (nodeByPath) {
       return [nodeByPath]
diff --git a/workspaces/arborist/lib/arborist/build-ideal-tree.js b/workspaces/arborist/lib/arborist/build-ideal-tree.js
index 9631a3eca890f..eb43e16ff7e46 100644
--- a/workspaces/arborist/lib/arborist/build-ideal-tree.js
+++ b/workspaces/arborist/lib/arborist/build-ideal-tree.js
@@ -103,7 +103,7 @@ module.exports = cls => class IdealTreeBuilder extends cls {
 
     // normalize trailing slash
     const registry = options.registry || 'https://registry.npmjs.org'
-    options.registry = this.registry = registry.replace(/\/+$/, '') + '/'
+    options.registry = this.registry = registry.replace(/(?<!\/)\/+$/, '') + '/'
 
     const {
       follow = false,