diff --git a/app/Http/Controllers/FemaleNameController.php b/app/Http/Controllers/FemaleNameController.php
index 81a4ac5..966364f 100644
--- a/app/Http/Controllers/FemaleNameController.php
+++ b/app/Http/Controllers/FemaleNameController.php
@@ -51,7 +51,7 @@ public function letter(Request $request): View
 
         $namesPagination = Cache::remember('female-letter-' . $requestedLetter . '-page-' . $requestedPage, 604800, fn () => Name::where('name', '!=', '_PRENOMS_RARES')
             ->where('gender', 'female')
-            ->where('name', 'like', $requestedLetter . '%')
+            ->where('name', 'like', Str::upper($requestedLetter) . '%')
             ->orderBy('total', 'desc')
             ->paginate(40)
         );
@@ -67,7 +67,7 @@ public function letter(Request $request): View
             'letters' => $letters,
             'names' => $names,
             'namesPagination' => $namesPagination,
-            'activeLetter' => Str::ucfirst($requestedLetter),
+            'activeLetter' => Str::upper($requestedLetter),
             'favorites' => $favoritedNamesForLoggedUser,
         ]);
     }
diff --git a/app/Http/Controllers/MaleNameController.php b/app/Http/Controllers/MaleNameController.php
index 83bbb8f..63e0664 100644
--- a/app/Http/Controllers/MaleNameController.php
+++ b/app/Http/Controllers/MaleNameController.php
@@ -51,7 +51,7 @@ public function letter(Request $request): View
 
         $namesPagination = Cache::remember('male-letter-' . $requestedLetter . '-page-' . $requestedPage, 604800, fn () => Name::where('name', '!=', '_PRENOMS_RARES')
             ->where('gender', 'male')
-            ->where('name', 'like', $requestedLetter . '%')
+            ->where('name', 'like', Str::upper($requestedLetter) . '%')
             ->orderBy('total', 'desc')
             ->paginate(40)
         );
@@ -67,7 +67,7 @@ public function letter(Request $request): View
             'letters' => $letters,
             'names' => $names,
             'namesPagination' => $namesPagination,
-            'activeLetter' => Str::ucfirst($requestedLetter),
+            'activeLetter' => Str::upper($requestedLetter),
             'favorites' => $favoritedNamesForLoggedUser,
         ]);
     }
diff --git a/app/Http/Controllers/MixteNameController.php b/app/Http/Controllers/MixteNameController.php
index abe2753..192830d 100644
--- a/app/Http/Controllers/MixteNameController.php
+++ b/app/Http/Controllers/MixteNameController.php
@@ -51,7 +51,7 @@ public function letter(Request $request): View
 
         $namesPagination = Cache::remember('mixte-letter-' . $requestedLetter . '-page-' . $requestedPage, 604800, fn () => Name::where('name', '!=', '_PRENOMS_RARES')
             ->where('unisex', 1)
-            ->where('name', 'like', $requestedLetter . '%')
+            ->where('name', 'like', Str::upper($requestedLetter) . '%')
             ->orderBy('total', 'desc')
             ->paginate(40)
         );
@@ -67,7 +67,7 @@ public function letter(Request $request): View
             'letters' => $letters,
             'names' => $names,
             'namesPagination' => $namesPagination,
-            'activeLetter' => Str::ucfirst($requestedLetter),
+            'activeLetter' => Str::upper($requestedLetter),
             'favorites' => $favoritedNamesForLoggedUser,
         ]);
     }