diff --git a/system/src/Grav/Framework/Flex/FlexCollection.php b/system/src/Grav/Framework/Flex/FlexCollection.php
index 68110a6451..cfa91008e9 100644
--- a/system/src/Grav/Framework/Flex/FlexCollection.php
+++ b/system/src/Grav/Framework/Flex/FlexCollection.php
@@ -440,7 +440,7 @@ public function render(string $layout = null, array $context = [])
                 ] + $context
             );
 
-            if ($debugger->enabled() && $grav['uri']->extension() !== 'json') {
+            if ($debugger->enabled() && $grav['uri']->getContentType() !== 'application/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 5cf838d63b..58bd7eb4da 100644
--- a/system/src/Grav/Framework/Flex/FlexObject.php
+++ b/system/src/Grav/Framework/Flex/FlexObject.php
@@ -627,7 +627,7 @@ public function render(string $layout = null, array $context = [])
                 ] + $context
             );
 
-            if ($debugger->enabled() && $grav['uri']->extension() !== 'json') {
+            if ($debugger->enabled() && $grav['uri']->getContentType() !== 'application/json') {
                 $name = $this->getKey() . ' (' . $type . ')';
                 $output = "\n<!–– START {$name} object ––>\n{$output}\n<!–– END {$name} object ––>\n";
             }