diff --git a/ext/dl/doc/dl.txt b/ext/dl/doc/dl.txt
index 44499bba15..51da92c49d 100644
--- a/ext/dl/doc/dl.txt
+++ b/ext/dl/doc/dl.txt
@@ -174,7 +174,7 @@ the class Handle keeps a handle to opened library.
 
 == PtrData class
 
-* ptr = PtrData.new(addr, [free = nil])
+* ptr = PtrData.new(addr, [size = 0, free = nil])
   * returns the PtrData object representing the pointer which indicates the
     address addr. GC frees the memory using the free function.
 
diff --git a/ext/dl/ptr.c b/ext/dl/ptr.c
index 21a703c24e..2ad022067c 100644
--- a/ext/dl/ptr.c
+++ b/ext/dl/ptr.c
@@ -197,8 +197,8 @@ rb_dlptr_initialize(int argc, VALUE argv[], VALUE self)
     f = rb_dlsym2csym(sym);
     break;
   default:
-    rb_bug("rb_dlptr_s_new");
-  };
+    rb_bug("rb_dlptr_initialize");
+  }
 
   if( p ){
     Data_Get_Struct(self, struct ptr_data, data);
@@ -230,8 +230,8 @@ rb_dlptr_s_malloc(int argc, VALUE argv[], VALUE klass)
     f = rb_dlsym2csym(sym);
     break;
   default:
-    rb_bug("rb_dlptr_s_new");
-  };
+    rb_bug("rb_dlptr_s_malloc");
+  }
 
   obj = rb_dlptr_malloc(s,f);