diff --git a/src/nxt_master_process.c b/src/nxt_master_process.c
index 12c61d16..e3d5382a 100644
--- a/src/nxt_master_process.c
+++ b/src/nxt_master_process.c
@@ -128,7 +128,7 @@ nxt_master_process_title(nxt_task_t *task)
 
     *p = '\0';
 
-    nxt_process_title(task, (char *) title);
+    nxt_process_title(task, "%s", (char *) title);
 }
 
 
diff --git a/src/nxt_process_title.c b/src/nxt_process_title.c
index 3e72f772..3c20ac59 100644
--- a/src/nxt_process_title.c
+++ b/src/nxt_process_title.c
@@ -247,7 +247,7 @@ nxt_process_title(nxt_task_t *task, const char *fmt, ...)
 #else /* !(NXT_SETPROCTITLE_ARGV) */
 
 void
-nxt_process_arguments(char **orig_argv, char ***orig_envp)
+nxt_process_arguments(nxt_task_t *task, char **orig_argv, char ***orig_envp)
 {
     nxt_process_argv = orig_argv;
     nxt_process_environ = orig_envp;