diff --git a/packages/cli/src/lib/walker-package-ranger.js b/packages/cli/src/lib/walker-package-ranger.js
index 45928824f..3fa983748 100644
--- a/packages/cli/src/lib/walker-package-ranger.js
+++ b/packages/cli/src/lib/walker-package-ranger.js
@@ -5,8 +5,7 @@ import { isBuiltin } from 'node:module';
 const SUPPORTED_EXPORT_CONDITIONS = ['import', 'module-sync', 'default'];
 const IMPORT_MAP_RESOLVED_PREFIX = '/~';
 const importMap = new Map();
-// TODO make diagnostics a Map
-const diagnostics = {};
+const diagnostics = new Map();
 
 function updateImportMap(key, value, resolvedRoot) {
   importMap.set(
@@ -25,7 +24,7 @@ function resolveBareSpecifier(specifier) {
   try {
     resolvedPath = import.meta.resolve(specifier);
   } catch (e) {
-    diagnostics[specifier] = `ERROR (${e.code}): unable to resolve specifier => \`${specifier}\` \n${e.message}`;
+    diagnostics.set(specifier, `ERROR (${e.code}): unable to resolve specifier => \`${specifier}\`\n${e.message}\n`);
   }
 
   return resolvedPath;
@@ -190,7 +189,7 @@ async function walkPackageForExports(dependency, packageJson, resolvedRoot) {
 
         if (!matched) {
           // ex. https://unpkg.com/browse/matches-selector@1.2.0/package.json
-          diagnostics[dependency] = `no supported export conditions (\`${SUPPORTED_EXPORT_CONDITIONS.join(', ')}\`) for dependency => \`${dependency}\``;
+          diagnostics.set(dependency, `no supported export conditions (\`${SUPPORTED_EXPORT_CONDITIONS.join(', ')}\`) for dependency => \`${dependency}\``);
         }
       } else {
         // handle (unconditional) subpath exports
@@ -212,7 +211,7 @@ async function walkPackageForExports(dependency, packageJson, resolvedRoot) {
     updateImportMap(dependency, 'index.js', resolvedRoot);
   } else {
     // ex: https://unpkg.com/browse/uuid@3.4.0/package.json
-    diagnostics[dependency] = `WARNING: No supported entry point detected for => \`${dependency}\``;
+    diagnostics.set(dependency, `WARNING: No supported entry point detected for => \`${dependency}\``);
   }
 }
 
@@ -244,7 +243,7 @@ async function walkPackageJson(packageJson = {}, walkedPackages = new Set()) {
           // https://github.com/nodejs/node/issues/56652
           // https://nodejs.org/api/modules.html#built-in-modules
           if (!isBuiltin(resolved)) {
-            diagnostics[dependency] = `WARNING: No package.json resolved for => \`${dependency}\`, resolved to \`${resolved}\``;
+            diagnostics.set(dependency, `WARNING: No package.json resolved for => \`${dependency}\`, resolved to \`${resolved}\``);
           }
         }
       }
diff --git a/packages/cli/src/plugins/resource/plugin-node-modules.js b/packages/cli/src/plugins/resource/plugin-node-modules.js
index 5e87f001d..2b5b551d7 100644
--- a/packages/cli/src/plugins/resource/plugin-node-modules.js
+++ b/packages/cli/src/plugins/resource/plugin-node-modules.js
@@ -80,14 +80,14 @@ class NodeModulesResource extends ResourceInterface {
       console.log('Generating import map from project dependencies...');
       const { importMap, diagnostics } = await walkPackageJson(userPackageJson);
 
-      if (Object.keys(diagnostics).length > 0) {
+      if (diagnostics.size > 0) {
         console.log('****************************************************************************');
 
-        Object.keys(diagnostics).forEach((diagnostic) => {
-          console.warn(`- ${diagnostics[diagnostic]}\n`);
+        diagnostics.forEach((value) => {
+          console.warn(`- ${value}`);
         });
 
-        console.log('>>> Learn more about these warnings at https://greenwoodjs.dev/docs/introduction/web-standards/#import-maps <<<');
+        console.log('\n>>> Some issue were detected, learn more about these warnings at https://greenwoodjs.dev/docs/introduction/web-standards/#import-maps');
         console.log('****************************************************************************');
       }