diff --git a/default_formatters/dictionary_formatter.py b/default_formatters/dictionary_formatter.py
index ff4075b..2dc5c46 100644
--- a/default_formatters/dictionary_formatter.py
+++ b/default_formatters/dictionary_formatter.py
@@ -5,6 +5,7 @@ from datetime import *
 import csv
 
 from PyTeX.formatter import Formatter
+from PyTeX.utils import ensure_file_integrity
 
 
 class DictionaryFormatter(Formatter):
@@ -74,7 +75,11 @@ class DictionaryFormatter(Formatter):
                             translation=translations[lang][key].strip()
                         )
                         lang_lines += '\n'
-
+                ensure_file_integrity(
+                    output_dir / self.file_name.format(language=lang),
+                    str(Path(relative_name).parent / self.file_name.format(language=lang)),
+                    last_build_info
+                )
                 (output_dir / self.file_name.format(language=lang)).write_text(''.join(lang_lines))
                 written_files.append(self.file_name.format(language=lang))
         return written_files
diff --git a/formatter/tex_formatter.py b/formatter/tex_formatter.py
index d854668..7ffaae8 100644
--- a/formatter/tex_formatter.py
+++ b/formatter/tex_formatter.py
@@ -6,7 +6,7 @@ from datetime import *
 
 from PyTeX.base import Attributes, Args
 from PyTeX.errors import *
-from PyTeX.utils import md5
+from PyTeX.utils import ensure_file_integrity
 
 from .formatter import Formatter
 
@@ -133,15 +133,7 @@ class TexFormatter(Formatter):
         if output_dir is None:
             output_dir = input_path.parent
         output_dir.mkdir(parents=True, exist_ok=True)
-        if (output_dir / self.file_name).exists():
-            found = False
-            for info in last_build_info:
-                if info['source file'] == relative_name:
-                    if not md5(output_dir / self.file_name) == info['md5sum']:
-                        raise ModifiedFileInBuildDirectoryError(str(output_dir / self.file_name))
-                    found = True
-            if not found:
-                raise UnknownFileInBuildDirectoryError(str(output_dir / self.file_name))
+        ensure_file_integrity(output_dir / self.file_name, str(Path(relative_name).parent / self.file_name), last_build_info)
 
         (output_dir / self.file_name).write_text(''.join(newlines))
         return [str(self.file_name)]
diff --git a/utils/__init__.py b/utils/__init__.py
index 5e98821..439bde2 100644
--- a/utils/__init__.py
+++ b/utils/__init__.py
@@ -1,5 +1,7 @@
 from. checksum import md5
+from .file_integrity import ensure_file_integrity
 
 __all__ = [
-    'md5'
+    'md5',
+    'ensure_file_integrity'
 ]
diff --git a/utils/file_integrity.py b/utils/file_integrity.py
new file mode 100644
index 0000000..13fe069
--- /dev/null
+++ b/utils/file_integrity.py
@@ -0,0 +1,18 @@
+from pathlib import Path
+from PyTeX.errors import *
+from .checksum import md5
+from typing import Optional, List, Dict
+
+
+def ensure_file_integrity(file: Path, output_file_name: str, build_info: Optional[List[Dict]] = None):
+    if file.exists():
+        if not build_info:
+            raise UnknownFileInBuildDirectoryError(str(file))
+        found = False
+        for info in build_info:
+            if info['name'] == output_file_name:
+                if not md5(file) == info['md5sum']:
+                    raise ModifiedFileInBuildDirectoryError(str(file))
+                found = True
+        if not found:
+            raise UnknownFileInBuildDirectoryError(str(file))