diff --git a/FileHeader.py b/FileHeader.py
index edcc4f7..701bf1f 100644
--- a/FileHeader.py
+++ b/FileHeader.py
@@ -601,13 +601,15 @@ def update_automatically(self, view, what):
             if search is not None:
                 var = search.group()
                 index = line.find(var)
-
+                line_header = None
+    
                 for i in range(index - 1, 0, -1):
                     if line[i] != ' ':
                         space_start = i + 1
                         line_header = line[:space_start]
                         break
-
+                if line_header is None:
+                    return
                 line_header = re.escape(line_header)
                 if what == LAST_MODIFIED_BY or what == FILE_NAME or \
                         what == FILE_NAME_WITHOUT_EXTENSION or \