diff --git a/builtin/fetch.c b/builtin/fetch.c
index 9191620e50..3d8f04b392 100644
--- a/builtin/fetch.c
+++ b/builtin/fetch.c
@@ -1817,6 +1817,7 @@ static int fetch_multiple(struct string_list *list, int max_children)
 		result = run_processes_parallel_tr2(max_children,
 						    &fetch_next_remote,
 						    &fetch_failed_to_start,
+						    NULL,
 						    &fetch_finished,
 						    &state,
 						    "fetch", "parallel/fetch");
diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index ae6174ab05..818494dd18 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -2295,7 +2295,7 @@ static int update_submodules(struct submodule_update_clone *suc)
 	int i;
 
 	run_processes_parallel_tr2(suc->max_jobs, update_clone_get_next_task,
-				   update_clone_start_failure,
+				   update_clone_start_failure, NULL,
 				   update_clone_task_finished, suc, "submodule",
 				   "parallel/update");
 
diff --git a/hook.c b/hook.c
index cab9cced82..a012c3d458 100644
--- a/hook.c
+++ b/hook.c
@@ -164,6 +164,7 @@ int run_found_hooks(const char *hook_name, const char *hook_path,
 	run_processes_parallel_tr2(options->jobs,
 				   pick_next_hook,
 				   notify_start_failure,
+				   NULL,
 				   notify_hook_finished,
 				   &cb_data,
 				   "hook",
diff --git a/run-command.c b/run-command.c
index 0bf771845e..3392640f17 100644
--- a/run-command.c
+++ b/run-command.c
@@ -1493,6 +1493,7 @@ struct parallel_processes {
 
 	get_next_task_fn get_next_task;
 	start_failure_fn start_failure;
+	feed_pipe_fn feed_pipe;
 	task_finished_fn task_finished;
 
 	struct {
@@ -1520,6 +1521,13 @@ static int default_start_failure(struct strbuf *out,
 	return 0;
 }
 
+static int default_feed_pipe(struct strbuf *pipe,
+			     void *pp_cb,
+			     void *pp_task_cb)
+{
+	return 1;
+}
+
 static int default_task_finished(int result,
 				 struct strbuf *out,
 				 void *pp_cb,
@@ -1550,6 +1558,7 @@ static void pp_init(struct parallel_processes *pp,
 		    int n,
 		    get_next_task_fn get_next_task,
 		    start_failure_fn start_failure,
+		    feed_pipe_fn feed_pipe,
 		    task_finished_fn task_finished,
 		    void *data)
 {
@@ -1568,6 +1577,7 @@ static void pp_init(struct parallel_processes *pp,
 	pp->get_next_task = get_next_task;
 
 	pp->start_failure = start_failure ? start_failure : default_start_failure;
+	pp->feed_pipe = feed_pipe ? feed_pipe : default_feed_pipe;
 	pp->task_finished = task_finished ? task_finished : default_task_finished;
 
 	pp->nr_processes = 0;
@@ -1665,6 +1675,37 @@ static int pp_start_one(struct parallel_processes *pp)
 	return 0;
 }
 
+static void pp_buffer_stdin(struct parallel_processes *pp)
+{
+	int i;
+	struct strbuf sb = STRBUF_INIT;
+
+	/* Buffer stdin for each pipe. */
+	for (i = 0; i < pp->max_processes; i++) {
+		if (pp->children[i].state == GIT_CP_WORKING &&
+		    pp->children[i].process.in > 0) {
+			int done;
+			strbuf_reset(&sb);
+			done = pp->feed_pipe(&sb, pp->data,
+					      pp->children[i].data);
+			if (sb.len) {
+				if (write_in_full(pp->children[i].process.in,
+					      sb.buf, sb.len) < 0) {
+					if (errno != EPIPE)
+						die_errno("write");
+					done = 1;
+				}
+			}
+			if (done) {
+				close(pp->children[i].process.in);
+				pp->children[i].process.in = 0;
+			}
+		}
+	}
+
+	strbuf_release(&sb);
+}
+
 static void pp_buffer_stderr(struct parallel_processes *pp, int output_timeout)
 {
 	int i;
@@ -1729,6 +1770,7 @@ static int pp_collect_finished(struct parallel_processes *pp)
 		pp->nr_processes--;
 		pp->children[i].state = GIT_CP_FREE;
 		pp->pfd[i].fd = -1;
+		pp->children[i].process.in = 0;
 		child_process_init(&pp->children[i].process);
 
 		if (i != pp->output_owner) {
@@ -1762,6 +1804,7 @@ static int pp_collect_finished(struct parallel_processes *pp)
 int run_processes_parallel(int n,
 			   get_next_task_fn get_next_task,
 			   start_failure_fn start_failure,
+			   feed_pipe_fn feed_pipe,
 			   task_finished_fn task_finished,
 			   void *pp_cb)
 {
@@ -1770,7 +1813,9 @@ int run_processes_parallel(int n,
 	int spawn_cap = 4;
 	struct parallel_processes pp;
 
-	pp_init(&pp, n, get_next_task, start_failure, task_finished, pp_cb);
+	sigchain_push(SIGPIPE, SIG_IGN);
+
+	pp_init(&pp, n, get_next_task, start_failure, feed_pipe, task_finished, pp_cb);
 	while (1) {
 		for (i = 0;
 		    i < spawn_cap && !pp.shutdown &&
@@ -1787,6 +1832,7 @@ int run_processes_parallel(int n,
 		}
 		if (!pp.nr_processes)
 			break;
+		pp_buffer_stdin(&pp);
 		pp_buffer_stderr(&pp, output_timeout);
 		pp_output(&pp);
 		code = pp_collect_finished(&pp);
@@ -1798,11 +1844,15 @@ int run_processes_parallel(int n,
 	}
 
 	pp_cleanup(&pp);
+
+	sigchain_pop(SIGPIPE);
+
 	return 0;
 }
 
 int run_processes_parallel_tr2(int n, get_next_task_fn get_next_task,
 			       start_failure_fn start_failure,
+			       feed_pipe_fn feed_pipe,
 			       task_finished_fn task_finished, void *pp_cb,
 			       const char *tr2_category, const char *tr2_label)
 {
@@ -1812,7 +1862,7 @@ int run_processes_parallel_tr2(int n, get_next_task_fn get_next_task,
 				   ((n < 1) ? online_cpus() : n));
 
 	result = run_processes_parallel(n, get_next_task, start_failure,
-					task_finished, pp_cb);
+					feed_pipe, task_finished, pp_cb);
 
 	trace2_region_leave(tr2_category, tr2_label, NULL);
 
diff --git a/run-command.h b/run-command.h
index 748d4fc2a7..41e36d26cb 100644
--- a/run-command.h
+++ b/run-command.h
@@ -419,6 +419,20 @@ typedef int (*start_failure_fn)(struct strbuf *out,
 				void *pp_cb,
 				void *pp_task_cb);
 
+/**
+ * This callback is called repeatedly on every child process who requests
+ * start_command() to create a pipe by setting child_process.in < 0.
+ *
+ * pp_cb is the callback cookie as passed into run_processes_parallel, and
+ * pp_task_cb is the callback cookie as passed into get_next_task_fn.
+ * The contents of 'send' will be read into the pipe and passed to the pipe.
+ *
+ * Return nonzero to close the pipe.
+ */
+typedef int (*feed_pipe_fn)(struct strbuf *pipe,
+			    void *pp_cb,
+			    void *pp_task_cb);
+
 /**
  * This callback is called on every child process that finished processing.
  *
@@ -453,10 +467,11 @@ typedef int (*task_finished_fn)(int result,
 int run_processes_parallel(int n,
 			   get_next_task_fn,
 			   start_failure_fn,
+			   feed_pipe_fn,
 			   task_finished_fn,
 			   void *pp_cb);
 int run_processes_parallel_tr2(int n, get_next_task_fn, start_failure_fn,
-			       task_finished_fn, void *pp_cb,
+			       feed_pipe_fn, task_finished_fn, void *pp_cb,
 			       const char *tr2_category, const char *tr2_label);
 
 #endif
diff --git a/submodule.c b/submodule.c
index 0b1d9c1dde..ea026a8195 100644
--- a/submodule.c
+++ b/submodule.c
@@ -1645,6 +1645,7 @@ int fetch_populated_submodules(struct repository *r,
 	run_processes_parallel_tr2(max_parallel_jobs,
 				   get_next_submodule,
 				   fetch_start_failure,
+				   NULL,
 				   fetch_finish,
 				   &spf,
 				   "submodule", "parallel/fetch");
diff --git a/t/helper/test-run-command.c b/t/helper/test-run-command.c
index 7ae03dc712..9348184d30 100644
--- a/t/helper/test-run-command.c
+++ b/t/helper/test-run-command.c
@@ -32,8 +32,13 @@ static int parallel_next(struct child_process *cp,
 		return 0;
 
 	strvec_pushv(&cp->args, d->argv);
+	cp->in = d->in;
+	cp->no_stdin = d->no_stdin;
 	strbuf_addstr(err, "preloaded output of a child\n");
 	number_callbacks++;
+
+	*task_cb = xmalloc(sizeof(int));
+	*(int*)(*task_cb) = 2;
 	return 1;
 }
 
@@ -55,6 +60,17 @@ static int task_finished(int result,
 	return 1;
 }
 
+static int test_stdin(struct strbuf *pipe, void *cb, void *task_cb)
+{
+	int *lines_remaining = task_cb;
+
+	if (*lines_remaining)
+		strbuf_addf(pipe, "sample stdin %d\n", --(*lines_remaining));
+
+	return !(*lines_remaining);
+}
+
+
 struct testsuite {
 	struct string_list tests, failed;
 	int next;
@@ -185,7 +201,7 @@ static int testsuite(int argc, const char **argv)
 		suite.tests.nr, max_jobs);
 
 	ret = run_processes_parallel(max_jobs, next_test, test_failed,
-				     test_finished, &suite);
+				     test_stdin, test_finished, &suite);
 
 	if (suite.failed.nr > 0) {
 		ret = 1;
@@ -413,15 +429,22 @@ int cmd__run_command(int argc, const char **argv)
 
 	if (!strcmp(argv[1], "run-command-parallel"))
 		exit(run_processes_parallel(jobs, parallel_next,
-					    NULL, NULL, &proc));
+					    NULL, NULL, NULL, &proc));
 
 	if (!strcmp(argv[1], "run-command-abort"))
 		exit(run_processes_parallel(jobs, parallel_next,
-					    NULL, task_finished, &proc));
+					    NULL, NULL, task_finished, &proc));
 
 	if (!strcmp(argv[1], "run-command-no-jobs"))
 		exit(run_processes_parallel(jobs, no_job,
-					    NULL, task_finished, &proc));
+					    NULL, NULL, task_finished, &proc));
+
+	if (!strcmp(argv[1], "run-command-stdin")) {
+		proc.in = -1;
+		proc.no_stdin = 0;
+		exit (run_processes_parallel(jobs, parallel_next, NULL,
+					     test_stdin, NULL, &proc));
+	}
 
 	fprintf(stderr, "check usage\n");
 	return 1;
diff --git a/t/t0061-run-command.sh b/t/t0061-run-command.sh
index 7d599675e3..87759482ad 100755
--- a/t/t0061-run-command.sh
+++ b/t/t0061-run-command.sh
@@ -143,6 +143,36 @@ test_expect_success 'run_command runs in parallel with more tasks than jobs avai
 	test_cmp expect actual
 '
 
+cat >expect <<-EOF
+preloaded output of a child
+listening for stdin:
+sample stdin 1
+sample stdin 0
+preloaded output of a child
+listening for stdin:
+sample stdin 1
+sample stdin 0
+preloaded output of a child
+listening for stdin:
+sample stdin 1
+sample stdin 0
+preloaded output of a child
+listening for stdin:
+sample stdin 1
+sample stdin 0
+EOF
+
+test_expect_success 'run_command listens to stdin' '
+	write_script stdin-script <<-\EOF &&
+	echo "listening for stdin:"
+	while read line; do
+		echo "$line"
+	done
+	EOF
+	test-tool run-command run-command-stdin 2 ./stdin-script 2>actual &&
+	test_cmp expect actual
+'
+
 cat >expect <<-EOF
 preloaded output of a child
 asking for a quick stop
