diff --git a/src/Twig/CanonicalizeRuntime.php b/src/Twig/CanonicalizeRuntime.php
index 6f4735a7..00595fd2 100644
--- a/src/Twig/CanonicalizeRuntime.php
+++ b/src/Twig/CanonicalizeRuntime.php
@@ -52,6 +52,14 @@ public function getCanonicalizedLocaleForMoment(): ?string
             }
         }
 
+        // Handle locales that has equal langage part and country part.
+        if (str_contains($locale, '-')) {
+            $localeParts = explode('-', strtolower($locale));
+            if ($localeParts[0] === $localeParts[1]) {
+                $locale = $localeParts[0];
+            }
+        }
+
         return $locale;
     }
 
diff --git a/tests/Twig/CanonicalizeRuntimeTest.php b/tests/Twig/CanonicalizeRuntimeTest.php
index cdf9cdd7..d01f8c7f 100644
--- a/tests/Twig/CanonicalizeRuntimeTest.php
+++ b/tests/Twig/CanonicalizeRuntimeTest.php
@@ -103,6 +103,7 @@ public function momentLocalesProvider(): array
             ['id', 'id'],
             ['is', 'is'],
             ['it', 'it'],
+            ['it', 'it-IT'],
             ['ja', 'ja'],
             ['jv', 'jv'],
             ['ka', 'ka'],