diff --git a/diff.c b/diff.c
index 648f6717a55..392530016fa 100644
--- a/diff.c
+++ b/diff.c
@@ -4278,35 +4278,33 @@ static void run_external_diff(const char *pgm,
 			      const char *xfrm_msg,
 			      struct diff_options *o)
 {
-	struct strvec argv = STRVEC_INIT;
-	struct strvec env = STRVEC_INIT;
 	struct diff_queue_struct *q = &diff_queued_diff;
+	struct child_process cmd = CHILD_PROCESS_INIT;
 
-	strvec_push(&argv, pgm);
-	strvec_push(&argv, name);
+	strvec_push(&cmd.args, pgm);
+	strvec_push(&cmd.args, name);
 
 	if (one && two) {
-		add_external_diff_name(o->repo, &argv, name, one);
+		add_external_diff_name(o->repo, &cmd.args, name, one);
 		if (!other)
-			add_external_diff_name(o->repo, &argv, name, two);
+			add_external_diff_name(o->repo, &cmd.args, name, two);
 		else {
-			add_external_diff_name(o->repo, &argv, other, two);
-			strvec_push(&argv, other);
-			strvec_push(&argv, xfrm_msg);
+			add_external_diff_name(o->repo, &cmd.args, other, two);
+			strvec_push(&cmd.args, other);
+			strvec_push(&cmd.args, xfrm_msg);
 		}
 	}
 
-	strvec_pushf(&env, "GIT_DIFF_PATH_COUNTER=%d", ++o->diff_path_counter);
-	strvec_pushf(&env, "GIT_DIFF_PATH_TOTAL=%d", q->nr);
+	strvec_pushf(&cmd.env, "GIT_DIFF_PATH_COUNTER=%d", ++o->diff_path_counter);
+	strvec_pushf(&cmd.env, "GIT_DIFF_PATH_TOTAL=%d", q->nr);
 
 	diff_free_filespec_data(one);
 	diff_free_filespec_data(two);
-	if (run_command_v_opt_cd_env(argv.v, RUN_USING_SHELL, NULL, env.v))
+	cmd.use_shell = 1;
+	if (run_command(&cmd))
 		die(_("external diff died, stopping at %s"), name);
 
 	remove_tempfile();
-	strvec_clear(&argv);
-	strvec_clear(&env);
 }
 
 static int similarity_index(struct diff_filepair *p)
diff --git a/run-command.c b/run-command.c
index f9a0b13f62f..25a978fb027 100644
--- a/run-command.c
+++ b/run-command.c
@@ -1038,7 +1038,7 @@ static int run_command_v_opt_1(struct child_process *cmd, int opt)
 
 int run_command_v_opt(const char **argv, int opt)
 {
-	return run_command_v_opt_cd_env(argv, opt, NULL, NULL);
+	return run_command_v_opt_cd_env_tr2(argv, opt, NULL, NULL, NULL);
 }
 
 int run_command_v_opt_tr2(const char **argv, int opt, const char *tr2_class)
@@ -1046,11 +1046,6 @@ int run_command_v_opt_tr2(const char **argv, int opt, const char *tr2_class)
 	return run_command_v_opt_cd_env_tr2(argv, opt, NULL, NULL, tr2_class);
 }
 
-int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env)
-{
-	return run_command_v_opt_cd_env_tr2(argv, opt, dir, env, NULL);
-}
-
 int run_command_v_opt_cd_env_tr2(const char **argv, int opt, const char *dir,
 				 const char *const *env, const char *tr2_class)
 {
diff --git a/run-command.h b/run-command.h
index 0af01bd9b67..2574d46cb70 100644
--- a/run-command.h
+++ b/run-command.h
@@ -152,7 +152,7 @@ struct child_process {
 /**
  * The functions: child_process_init, start_command, finish_command,
  * run_command, run_command_l_opt, run_command_v_opt,
- * run_command_v_opt_cd_env, child_process_clear do the following:
+ * child_process_clear do the following:
  *
  * - If a system call failed, errno is set and -1 is returned. A diagnostic
  *   is printed.
@@ -263,7 +263,6 @@ int run_command_v_opt_tr2(const char **argv, int opt, const char *tr2_class);
  * env (the environment) is to be formatted like environ: "VAR=VALUE".
  * To unset an environment variable use just "VAR".
  */
-int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env);
 int run_command_v_opt_cd_env_tr2(const char **argv, int opt, const char *dir,
 				 const char *const *env, const char *tr2_class);
 
diff --git a/tmp-objdir.h b/tmp-objdir.h
index 76efc7edee5..c96aa77396d 100644
--- a/tmp-objdir.h
+++ b/tmp-objdir.h
@@ -10,9 +10,11 @@
  *
  * Example:
  *
+ *	struct child_process cmd = CHILD_PROCESS_INIT;
+ *	...
  *	struct tmp_objdir *t = tmp_objdir_create("incoming");
- *	if (!run_command_v_opt_cd_env(cmd, 0, NULL, tmp_objdir_env(t)) &&
- *	    !tmp_objdir_migrate(t))
+ *      strvec_pushl(&cmd.env, tmp_objdir_env(t));
+ *	if (!run_command(&cmd) && !tmp_objdir_migrate(t))
  *		printf("success!\n");
  *	else
  *		die("failed...tmp_objdir will clean up for us");
