diff --git a/framework/CHANGELOG.md b/framework/CHANGELOG.md
index eabd0fd1e5..5fea5f0aa6 100644
--- a/framework/CHANGELOG.md
+++ b/framework/CHANGELOG.md
@@ -4,6 +4,7 @@ Yii Framework 2 Change Log
 2.0.0 under development
 -----------------------
 
+- Bug #5260: `yii\i18n\Formatter::decimalSeparator` and `yii\i18n\Formatter::thousandSeparator` where not configurable when intl is not installed (execut, cebe)
 - Bug: Date and time formatting now assumes UTC as the timezone for input dates unless a timezone is explicitly given (cebe)
 - Enh #4275: Added `removeChildren()` to `yii\rbac\ManagerInterface` and implementations (samdark)
 
diff --git a/framework/i18n/Formatter.php b/framework/i18n/Formatter.php
index 3837ecc5d5..ea36c0d891 100644
--- a/framework/i18n/Formatter.php
+++ b/framework/i18n/Formatter.php
@@ -208,8 +208,12 @@ class Formatter extends Component
         }
         $this->_intlLoaded = extension_loaded('intl');
         if (!$this->_intlLoaded) {
-            $this->decimalSeparator = '.';
-            $this->thousandSeparator = ',';
+            if ($this->decimalSeparator === null) {
+                $this->decimalSeparator = '.';
+            }
+            if ($this->thousandSeparator === null) {
+                $this->thousandSeparator = ',';
+            }
         }
     }