diff --git a/tests/pexpects/history.py b/tests/pexpects/history.py
index e62b262c8..dd0be4289 100644
--- a/tests/pexpects/history.py
+++ b/tests/pexpects/history.py
@@ -14,9 +14,10 @@
 from pexpect_helper import SpawnedProc
 import os
 
-os.environ["PAGER"] = "cat"
+env = os.environ.copy()
+env["PAGER"] = "cat"
 
-sp = SpawnedProc(env=os.environ.copy())
+sp = SpawnedProc(env=env)
 
 send, sendline, sleep, expect_prompt, expect_re, expect_str = (
     sp.send,
@@ -108,8 +109,8 @@ expect_prompt("count hello 0\r\n")
 # sent above that matches).
 sendline("history delete -p 'echo hello'")
 expect_re("history delete -p 'echo hello'\r\n")
-expect_re("\[1\] echo hello AGAIN\r\n")
-expect_re("\[2\] echo hello again\r\n\r\n")
+expect_re(r"\[1\] echo hello AGAIN\r\n")
+expect_re(r"\[2\] echo hello again\r\n\r\n")
 expect_re(
     "Enter nothing to cancel the delete, or\r\nEnter one or more of the entry IDs or ranges like '5..12', separated by a space.\r\nFor example '7 10..15 35 788..812'.\r\nEnter 'all' to delete all the matching entries.\r\n"
 )