diff --git a/dangerfile.py b/dangerfile.py
index ee77f13cd1..531e05bb18 100644
--- a/dangerfile.py
+++ b/dangerfile.py
@@ -23,11 +23,13 @@ import gitlab
 def added_lines(target_branch, paths):
     import subprocess
 
-    subprocess.check_output(
-        ["/usr/bin/git", "fetch", "--depth", "1", "origin", target_branch]
-    )
+    # Hazard fetches the target branch itself, so there is no need to fetch it
+    # explicitly using `git fetch --depth 1000 origin <target_branch>`.  The
+    # refs/remotes/origin/<target_branch> ref is also expected to be readily
+    # usable by the time this file is executed.
+
     diff = subprocess.check_output(
-        ["/usr/bin/git", "diff", "FETCH_HEAD..", "--"] + paths
+        ["/usr/bin/git", "diff", f"origin/{target_branch}...", "--"] + paths
     )
     added_lines = []
     for line in diff.splitlines():