diff --git a/lib/roo/base.rb b/lib/roo/base.rb
index a620841a..4cd3925d 100644
--- a/lib/roo/base.rb
+++ b/lib/roo/base.rb
@@ -160,13 +160,8 @@ def to_matrix(from_row = nil, from_column = nil, to_row = nil, to_column = nil,
     end)
   end
 
-  def inspect(debug = false)
-    if debug
-      # call to_s method defined on subclasses
-      to_s
-    else
-      "<##{ self.class }:#{ self.object_id.to_s(8) } #{ self.instance_variables.join(' ') }>"
-    end
+  def inspect
+    "<##{ self.class }:#{ self.object_id.to_s(8) } #{ self.instance_variables.join(' ') }>"
   end
 
   # find a row either by row number or a condition