diff --git a/system/src/Grav/Common/Uri.php b/system/src/Grav/Common/Uri.php
index 2d4386017..dcd9c27a8 100644
--- a/system/src/Grav/Common/Uri.php
+++ b/system/src/Grav/Common/Uri.php
@@ -1407,14 +1407,13 @@ class Uri
      */
     public function getContentType($short = true)
     {
-        if (isset($_SERVER['CONTENT_TYPE'])) {
-            $content_type = $_SERVER['CONTENT_TYPE'];
+       $content_type = $_SERVER['CONTENT_TYPE'] ?? $_SERVER['HTTP_CONTENT_TYPE'] ?? $_SERVER['HTTP_ACCEPT'] ?? null;
+        if ($content_type) {
             if ($short) {
                 return Utils::substrToString($content_type, ';');
             }
-            return $content_type;
         }
-        return null;
+        return $content_type;
     }
 
     /**
diff --git a/system/src/Grav/Framework/Flex/FlexCollection.php b/system/src/Grav/Framework/Flex/FlexCollection.php
index cfa91008e..3e9302cb8 100644
--- a/system/src/Grav/Framework/Flex/FlexCollection.php
+++ b/system/src/Grav/Framework/Flex/FlexCollection.php
@@ -440,7 +440,8 @@ class FlexCollection extends ObjectCollection implements FlexCollectionInterface
                 ] + $context
             );
 
-            if ($debugger->enabled() && $grav['uri']->getContentType() !== 'application/json') {
+            if ($debugger->enabled() &&
+                !($grav['uri']->getContentType() === 'application/json' || $grav['uri']->extension() === 'json')) {
                 $output = "\n<!–– START {$type} collection ––>\n{$output}\n<!–– END {$type} collection ––>\n";
             }
 
diff --git a/system/src/Grav/Framework/Flex/FlexObject.php b/system/src/Grav/Framework/Flex/FlexObject.php
index 58bd7eb4d..14f28f9b6 100644
--- a/system/src/Grav/Framework/Flex/FlexObject.php
+++ b/system/src/Grav/Framework/Flex/FlexObject.php
@@ -627,7 +627,8 @@ class FlexObject implements FlexObjectInterface, FlexAuthorizeInterface
                 ] + $context
             );
 
-            if ($debugger->enabled() && $grav['uri']->getContentType() !== 'application/json') {
+            if ($debugger->enabled() &&
+                !($grav['uri']->getContentType() === 'application/json' || $grav['uri']->extension() === 'json')) {
                 $name = $this->getKey() . ' (' . $type . ')';
                 $output = "\n<!–– START {$name} object ––>\n{$output}\n<!–– END {$name} object ––>\n";
             }