diff --git a/src/flake8/processor.py b/src/flake8/processor.py
index 6b7d3c4..f632388 100644
--- a/src/flake8/processor.py
+++ b/src/flake8/processor.py
@@ -92,8 +92,6 @@ class FileProcessor:
         self.indent_level = 0
         #: Number of spaces used for indentation
         self.indent_size = options.indent_size
-        #: String representing the space indentation (DEPRECATED)
-        self.indent_size_str = str(self.indent_size)
         #: Line number in the file
         self.line_number = 0
         #: Current logical line