diff --git a/pydiffchecker/line_shift_checker.py b/pydiffchecker/line_shift_checker.py
index 913a2c7..8180cf3 100644
--- a/pydiffchecker/line_shift_checker.py
+++ b/pydiffchecker/line_shift_checker.py
@@ -33,18 +33,26 @@ class LineShiftChecker:
         return file_list
 
     def __get_shifted_lines_in_file(self, file_info) -> 'Dict[str, str | None]':
-        lines_in_source_file = self.__count_lines_in_source_file(file_info['src'])
-        process_output = subprocess_readlines(['git', 'diff', f'-U{lines_in_source_file}',
+        process_output = subprocess_readlines(['git', 'diff',
                                                self.revision_since, self.revision_until, '--',
                                                file_info['src'], file_info['dst']])
 
         diff_started = False
         shifted_lines = {}
+        old_start = 1
+        new_start = 1
         for line in process_output:
             matches = re.search(LineShiftChecker.DIFF_BLOCK_REGEX, line)
             if matches:
-                old_start = int(matches.group(1))
-                new_start = int(matches.group(3))
+                diff_block_src_start = int(matches.group(1))
+                diff_block_dst_start = int(matches.group(3))
+
+                # fill shifted lines between 2 diff blocks
+                for i in range(0, diff_block_src_start - old_start):
+                    shifted_lines[f'{file_info["src"]}:{old_start+i}'] = f'{file_info["dst"]}:{new_start+i}'
+
+                old_start = diff_block_src_start
+                new_start = diff_block_dst_start
                 diff_started = True
                 continue
 
@@ -61,11 +69,10 @@ class LineShiftChecker:
                 shifted_lines[f'{file_info["src"]}:{old_start}'] = None
                 old_start += 1
 
-        if not diff_started:
-            # it was a pure rename, so no diff blocks were returned,
-            # we just put the lines into the dict
-            shifted_lines = {f'{file_info["src"]}:{i}': f'{file_info["dst"]}:{i}'
-                             for i in range(0, lines_in_source_file)}
+        # fill shifted lines until end of file
+        lines_in_source_file = self.__count_lines_in_source_file(file_info['src'])
+        for i in range(0, lines_in_source_file - old_start + 1):
+            shifted_lines[f'{file_info["src"]}:{old_start+i}'] = f'{file_info["dst"]}:{new_start+i}'
 
         assert lines_in_source_file == len(shifted_lines)