diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1cfec1a..11ba76b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,11 @@
+## v4.1.1 (2020-05-21)
+
+#### :bug: Bug Fix
+* [#210](https://github.com/ember-cli/ember-cli-version-checker/pull/210) [v4] Fix hasSingleImplementation ([@xg-wang](https://github.com/xg-wang))
+
+#### Committers: 1
+- Thomas Wang ([@xg-wang](https://github.com/xg-wang))
+-
 ##  v4.1.0 (2020-01-17)
 
 #### :rocket: Enhancement
diff --git a/package.json b/package.json
index 4c95776..aab92aa 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "ember-cli-version-checker",
-  "version": "4.1.0",
+  "version": "4.1.1",
   "description": "Determine if your addon is being used by a minimum version of Ember CLI.",
   "homepage": "https://github.com/rwjblue/ember-cli-version-checker",
   "bugs": {
diff --git a/src/dependency-version-checker.js b/src/dependency-version-checker.js
index dd74a39..04875de 100644
--- a/src/dependency-version-checker.js
+++ b/src/dependency-version-checker.js
@@ -1,16 +1,18 @@
 'use strict';
-const fs = require('fs');
 const semver = require('semver');
 
+/*
+ * Retrieve the version field from the package.json file contents.
+ * NOTE: the callers have already checked that the filePath is not null/undefined.
+ */
 function getVersionFromJSONFile(filePath) {
-  if (fs.existsSync(filePath)) {
-    let content = fs.readFileSync(filePath);
-
-    try {
-      return JSON.parse(content).version;
-    } catch (exception) {
-      return null;
-    }
+  try {
+    // Use the require cache to avoid file I/O after first call on a given path.
+    let pkg = require(filePath);
+    return pkg.version;
+  } catch (err) {
+    // file doesn't exist or is not a file or is not parseable.
+    return null;
   }
 }
 
diff --git a/src/utils/single-implementation.js b/src/utils/single-implementation.js
index 09258d3..8a6909b 100644
--- a/src/utils/single-implementation.js
+++ b/src/utils/single-implementation.js
@@ -22,7 +22,7 @@ function hasSingleImplementation(targetName, project) {
 
   for (let { name, root } of allAddons(project)) {
     if (targetName === name) {
-      if (lastRoot !== undefined) {
+      if (lastRoot !== undefined && lastRoot !== root) {
         map.set(targetName, false);
         return false;
       } else {
diff --git a/tests/index-tests.js b/tests/index-tests.js
index 42f89b9..72fc524 100644
--- a/tests/index-tests.js
+++ b/tests/index-tests.js
@@ -556,11 +556,17 @@ describe('ember-cli-version-checker', function() {
                 addons: [
                   {
                     name: 'foo',
-                    root: 'node_modules/fake-addon/node_modeuls/foo',
+                    root: 'node_modules/fake-addon/node_modules/foo',
                   },
                   {
                     name: 'bar',
                     root: 'node_modules/fake-addon/node_modules/bar',
+                    addons: [
+                      {
+                        name: 'foo',
+                        root: 'node_modules/fake-addon/node_modules/foo',
+                      },
+                    ],
                   },
                 ],
               },
@@ -591,7 +597,7 @@ describe('ember-cli-version-checker', function() {
           });
 
           it('has a working #filterAddonsByName', () => {
-            assert.equal(checker.filterAddonsByName('foo').length, 1);
+            assert.equal(checker.filterAddonsByName('foo').length, 2);
             assert.equal(checker.filterAddonsByName('top').length, 1);
             assert.equal(checker.filterAddonsByName('bar').length, 2);
             assert.equal(
@@ -612,7 +618,7 @@ describe('ember-cli-version-checker', function() {
           it('has a functioning allAddons iterator', function() {
             assert.deepEqual(
               [...checker.allAddons()].map(x => x.name),
-              ['top', 'bar', 'fake-addon', 'foo', 'bar']
+              ['top', 'bar', 'fake-addon', 'foo', 'bar', 'foo']
             );
           });
         });