diff --git a/src/TamerLib/tm.php b/src/TamerLib/tm.php
index da11340..b747864 100644
--- a/src/TamerLib/tm.php
+++ b/src/TamerLib/tm.php
@@ -293,7 +293,6 @@
                 self::$supervisor->spawnWorker($path, $count, $channel);
             }
 
-            var_dump('monitoring');
             self::monitor(-1);
         }
 
@@ -586,6 +585,16 @@
                 throw new RuntimeException(sprintf('Attempting to addFunction() in \'%s\' mode, only workers can preform addFunction().', self::$mode));
             }
 
+            if (!preg_match('/^[a-zA-Z_\x80-\xff][a-zA-Z0-9_\x80-\xff]*$/', $function))
+            {
+                throw new InvalidArgumentException("Invalid function name: $function");
+            }
+
+            if(method_exists(__CLASS__, $function))
+            {
+                throw new InvalidArgumentException(sprintf('Attempting to addFunction() with a function name of \'%s\', this is a reserved function name.', $function));
+            }
+
             self::$function_pointers[$function] = $callback;
         }