diff --git a/lib/pagelib.php b/lib/pagelib.php
index 4536a3f8286..ea9ee147791 100644
--- a/lib/pagelib.php
+++ b/lib/pagelib.php
@@ -61,6 +61,14 @@ function page_map_class($type, $classname = NULL) {
     }
 
     if(!class_exists($mappings[$type])) {
+        print_object('Debug info - type:');
+        var_dump($type);
+        print_object('Debug info - classname:');
+        var_dump($classname);
+        print_object('Debug info - mappings:');
+        print_object($mappings);
+        print_object('Debug_backtrace():');
+        print_object(debug_backtrace());
         error('Page class mapping for id "'.$type.'" exists but class "'.$mappings[$type].'" is not defined');
     }