diff --git a/scripts/continuum_save.sh b/scripts/continuum_save.sh
index c85f68a..29b24ac 100755
--- a/scripts/continuum_save.sh
+++ b/scripts/continuum_save.sh
@@ -35,8 +35,11 @@ fetch_and_run_tmux_resurrect_save_script() {
 }
 
 main() {
-	if supported_tmux_version_ok && auto_save_not_disabled && enough_time_since_last_run_passed; then
-		fetch_and_run_tmux_resurrect_save_script
-	fi
+	(
+		flock -n 101 || return  # The code below is not thread-safe.
+		if supported_tmux_version_ok && auto_save_not_disabled && enough_time_since_last_run_passed; then
+			fetch_and_run_tmux_resurrect_save_script
+		fi
+	) 101>/tmp/tmux-continuum-autosave.lockfile
 }
 main