diff --git a/add-patch.c b/add-patch.c
index 0997d4af73..b2fbd8cbf3 100644
--- a/add-patch.c
+++ b/add-patch.c
@@ -300,6 +300,7 @@ static void err(struct add_p_state *s, const char *fmt, ...)
 	va_end(args);
 }
 
+LAST_ARG_MUST_BE_NULL
 static void setup_child_process(struct add_p_state *s,
 				struct child_process *cp, ...)
 {
diff --git a/attr.h b/attr.h
index 127998ae01..afa33ce3be 100644
--- a/attr.h
+++ b/attr.h
@@ -190,6 +190,8 @@ struct attr_check {
 };
 
 struct attr_check *attr_check_alloc(void);
+
+LAST_ARG_MUST_BE_NULL
 struct attr_check *attr_check_initl(const char *, ...);
 struct attr_check *attr_check_dup(const struct attr_check *check);
 
diff --git a/hook.h b/hook.h
index 19ab9a5806..6511525aeb 100644
--- a/hook.h
+++ b/hook.h
@@ -86,5 +86,6 @@ int run_hooks(const char *hook_name);
  * argument. These things will be used as positional arguments to the
  * hook. This function behaves like the old run_hook_le() API.
  */
+LAST_ARG_MUST_BE_NULL
 int run_hooks_l(const char *hook_name, ...);
 #endif
diff --git a/scalar.c b/scalar.c
index fb2940c2a0..552ac8f0d9 100644
--- a/scalar.c
+++ b/scalar.c
@@ -70,6 +70,7 @@ static void setup_enlistment_directory(int argc, const char **argv,
 	strbuf_release(&path);
 }
 
+LAST_ARG_MUST_BE_NULL
 static int run_git(const char *arg, ...)
 {
 	struct child_process cmd = CHILD_PROCESS_INIT;