diff --git a/kittens/diff/highlight.py b/kittens/diff/highlight.py
index da7650cde..c159ff7e9 100644
--- a/kittens/diff/highlight.py
+++ b/kittens/diff/highlight.py
@@ -122,6 +122,8 @@ def highlight_line(line):
 def highlight_for_diff(path, aliases):
     ans = []
     lines = lines_for_path(path)
+    if len(lines) > 10000:
+        return ans
     hd = highlight_data('\n'.join(lines), path, aliases)
     if hd is not None:
         for line in hd.splitlines():