diff --git a/PyTeX/format/auto_format.py b/PyTeX/format/auto_format.py
index 365ecaa..d4dd30a 100644
--- a/PyTeX/format/auto_format.py
+++ b/PyTeX/format/auto_format.py
@@ -9,7 +9,7 @@ from .dtx_formatter import DTXFormatter
 from .pytex_formatter import PyTeXFormatter
 from .git_version_info import GitVersionInfo
 from .default_macros import get_default_macros
-
+from .enums import TeXType
 
 def formatter_from_file_extension(
         input_file: Path,
@@ -25,12 +25,20 @@ def formatter_from_file_extension(
         'cls.pytex': SimpleTeXFormatter,
         'dict.pytex': DictFormatter
     }
+    switcher2: Dict[str, TeXType] = {
+        'dtx.pytex': TeXType.TeXDocstrip,
+        'sty.pytex': TeXType.TeXPackage,
+        'cls.pytex': TeXType.TeXClass,
+        'dict.pytex': TeXType.TeXDictionary
+    }
     #  TODO: other formatters
     try:
         [name, extension] = input_file.name.split('.', maxsplit=1)
     except:
         raise NotImplementedError
 
+    config.tex_type = switcher2[extension]  # This sets the textype from file extension
+
     formatter = switcher[extension](
         input_file=input_file,
         config=config,
diff --git a/PyTeX/format/pytex_formatter.py b/PyTeX/format/pytex_formatter.py
index e8a38d7..6b31cea 100644
--- a/PyTeX/format/pytex_formatter.py
+++ b/PyTeX/format/pytex_formatter.py
@@ -12,6 +12,7 @@ from abc import ABC, abstractmethod
 from .enums import *
 from datetime import *
 
+
 class PyTeXFormatter(FormatterIF, ABC):
     def __init__(
             self,
diff --git a/PyTeX/format/simple_tex_formatter.py b/PyTeX/format/simple_tex_formatter.py
index 625cb2c..81f5a87 100644
--- a/PyTeX/format/simple_tex_formatter.py
+++ b/PyTeX/format/simple_tex_formatter.py
@@ -2,12 +2,20 @@ from .formatting_config import FormattingConfig
 from .tex_formatter import TexFormatter
 from pathlib import Path
 from typing import Optional, List, Tuple, Dict
-from .enums import TeXFlavour
+from .enums import TeXFlavour, TeXType
 
 
 class SimpleTeXFormatter(TexFormatter):
+    @property
+    def output_file(self) -> str:
+        switcher = {
+            TeXType.TeXClass: '.cls',
+            TeXType.TeXPackage: '.sty',
+        }
+        return self.name + switcher[self.config.tex_type]
+
     def open_output_stream(self, build_dir: Path):
-        out_file = build_dir / self.input_file.with_suffix('').name
+        out_file = build_dir / self.output_file
         if out_file.exists():
             raise NotImplementedError
         else:
@@ -26,7 +34,7 @@ class SimpleTeXFormatter(TexFormatter):
 
     @property
     def output_files(self) -> List[str]:
-        return [self.input_file.with_suffix('').name]
+        return [self.output_file]
 
     def _post_process_line(self, line: str) -> str:
         if self.config.tex_flavour == TeXFlavour.LaTeX2e: