diff --git a/changes.d/6316.fix.md b/changes.d/6316.fix.md
new file mode 100644
index 00000000000..956b0c06066
--- /dev/null
+++ b/changes.d/6316.fix.md
@@ -0,0 +1 @@
+Prevent validate step of VR changing CLI options.
diff --git a/cylc/flow/scripts/validate_reinstall.py b/cylc/flow/scripts/validate_reinstall.py
index fa53461b2c3..d634080a50d 100644
--- a/cylc/flow/scripts/validate_reinstall.py
+++ b/cylc/flow/scripts/validate_reinstall.py
@@ -39,6 +39,7 @@
   in the installed workflow to ensure the change can be safely applied.
 """
 
+from copy import copy
 import sys
 from typing import TYPE_CHECKING
 
@@ -171,7 +172,11 @@ async def vr_cli(parser: COP, options: 'Values', workflow_id: str):
 
     # Run cylc validate
     log_subcommand('validate --against-source', workflow_id)
-    await cylc_validate(parser, options, workflow_id)
+
+    # Copy options in case validate decides to store information
+    # in the options object:
+    val_opts = copy(options)
+    await cylc_validate(parser, val_opts, workflow_id)
 
     # Unset options that do not apply after validation:
     delattr(options, 'against_source')
diff --git a/tests/functional/cylc-combination-scripts/09-vr-icp-now.t b/tests/functional/cylc-combination-scripts/09-vr-icp-now.t
new file mode 100644
index 00000000000..233978618c6
--- /dev/null
+++ b/tests/functional/cylc-combination-scripts/09-vr-icp-now.t
@@ -0,0 +1,38 @@
+#!/usr/bin/env bash
+# THIS FILE IS PART OF THE CYLC WORKFLOW ENGINE.
+# Copyright (C) NIWA & British Crown (Met Office) & Contributors.
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+#------------------------------------------------------------------------------
+# Ensure that validate step of Cylc VR cannot change the options object.
+# See https://github.com/cylc/cylc-flow/issues/6262
+
+. "$(dirname "$0")/test_header"
+set_test_number 2
+
+WORKFLOW_ID=$(workflow_id)
+
+cp -r "${TEST_SOURCE_DIR}/${TEST_NAME_BASE}/flow.cylc" .
+
+run_ok "${TEST_NAME_BASE}-vip" \
+    cylc vip . \
+        --workflow-name "${WORKFLOW_ID}" \
+        --no-detach \
+        --no-run-name
+
+echo "# Some Comment" >> flow.cylc
+
+run_ok "${TEST_NAME_BASE}-vr" \
+    cylc vr "${WORKFLOW_ID}"
diff --git a/tests/functional/cylc-combination-scripts/09-vr-icp-now/flow.cylc b/tests/functional/cylc-combination-scripts/09-vr-icp-now/flow.cylc
new file mode 100644
index 00000000000..7aaf80f8d36
--- /dev/null
+++ b/tests/functional/cylc-combination-scripts/09-vr-icp-now/flow.cylc
@@ -0,0 +1,7 @@
+[scheduling]
+    initial cycle point = now
+    [[graph]]
+        PT1M = foo
+[runtime]
+    [[foo]]
+        script = cylc stop "${CYLC_WORKFLOW_ID}"