diff --git a/cylc/flow/scripts/validate_install_play.py b/cylc/flow/scripts/validate_install_play.py
index 9343289f987..d701eb02315 100644
--- a/cylc/flow/scripts/validate_install_play.py
+++ b/cylc/flow/scripts/validate_install_play.py
@@ -86,7 +86,7 @@ def get_option_parser() -> COP:
         # no sense in a VIP context.
         if option.kwargs.get('dest') != 'against_source':
             parser.add_option(*option.args, **option.kwargs)
-
+    parser.set_defaults(is_validate=True)
     return parser
 
 
@@ -103,6 +103,9 @@ def main(parser: COP, options: 'Values', workflow_id: Optional[str] = None):
     log_subcommand('validate', source)
     asyncio.run(cylc_validate(parser, options, str(source)))
 
+    # Unset is validate after validation.
+    delattr(options, 'is_validate')
+
     log_subcommand('install', source)
     _, workflow_id = asyncio.run(cylc_install(options, workflow_id))
 
diff --git a/cylc/flow/scripts/validate_reinstall.py b/cylc/flow/scripts/validate_reinstall.py
index 0733512ddad..de1be6dea82 100644
--- a/cylc/flow/scripts/validate_reinstall.py
+++ b/cylc/flow/scripts/validate_reinstall.py
@@ -97,6 +97,7 @@ def get_option_parser() -> COP:
     )
     for option in VR_OPTIONS:
         parser.add_option(*option.args, **option.kwargs)
+    parser.set_defaults(is_validate=True)
     return parser
 
 
@@ -169,6 +170,9 @@ async def vr_cli(parser: COP, options: 'Values', workflow_id: str):
     log_subcommand('validate --against-source', workflow_id)
     await cylc_validate(parser, options, workflow_id)
 
+    # Unset is validate after validation.
+    delattr(options, 'is_validate')
+
     log_subcommand('reinstall', workflow_id)
     reinstall_ok = await cylc_reinstall(
         options, workflow_id,