diff --git a/src/bin/pg_ctl/pg_ctl.c b/src/bin/pg_ctl/pg_ctl.c
index 2818af51958..ce065296d92 100644
--- a/src/bin/pg_ctl/pg_ctl.c
+++ b/src/bin/pg_ctl/pg_ctl.c
@@ -78,7 +78,7 @@ typedef enum
 
 static bool do_wait = true;
 static int	wait_seconds = DEFAULT_WAIT;
-static bool wait_seconds_arg = false;
+pg_attribute_unused() static bool wait_seconds_arg = false;
 static bool silent_mode = false;
 static ShutdownMode shutdown_mode = FAST_MODE;
 static int	sig = SIGINT;		/* default */
@@ -90,10 +90,10 @@ static char *post_opts = NULL;
 static const char *progname;
 static char *log_file = NULL;
 static char *exec_path = NULL;
-static char *event_source = NULL;
-static char *register_servicename = "PostgreSQL";	/* FIXME: + version ID? */
-static char *register_username = NULL;
-static char *register_password = NULL;
+pg_attribute_unused() static char *event_source = NULL;
+pg_attribute_unused() static char *register_servicename = "PostgreSQL"; /* FIXME: + version ID? */
+pg_attribute_unused() static char *register_username = NULL;
+pg_attribute_unused() static char *register_password = NULL;
 static char *argv0 = NULL;
 static bool allow_core_files = false;
 static time_t start_time;