diff --git a/src/plugins/relay/api/relay-api-msg.c b/src/plugins/relay/api/relay-api-msg.c
index 95eb53617..56b184ab8 100644
--- a/src/plugins/relay/api/relay-api-msg.c
+++ b/src/plugins/relay/api/relay-api-msg.c
@@ -385,6 +385,7 @@ relay_api_msg_buffer_to_json (struct t_gui_buffer *buffer,
         lines = lines_free;
     MSG_ADD_STR_PTR("type", ptr_string);
     MSG_ADD_HDATA_STR_COLORS("title", "title");
+    MSG_ADD_HDATA_STR_COLORS("input_prompt", "input_prompt");
     MSG_ADD_HDATA_STR("input", "input_buffer");
     MSG_ADD_HDATA_VAR(Number, "input_position", integer, "input_buffer_pos");
     MSG_ADD_HDATA_VAR(Bool, "input_multiline", integer, "input_multiline");
diff --git a/src/plugins/relay/api/relay-api.c b/src/plugins/relay/api/relay-api.c
index 990ff1425..34c7e14f0 100644
--- a/src/plugins/relay/api/relay-api.c
+++ b/src/plugins/relay/api/relay-api.c
@@ -126,7 +126,9 @@ relay_api_hook_signals (struct t_relay_client *client)
         if (!RELAY_API_DATA(client, hook_signal_input))
         {
             RELAY_API_DATA(client, hook_signal_input) =
-                weechat_hook_signal ("input_text_changed;input_text_cursor_moved",
+                weechat_hook_signal ("input_prompt_changed;"
+                                     "input_text_changed;"
+                                     "input_text_cursor_moved",
                                      &relay_api_protocol_signal_input_cb,
                                      client, NULL);
         }
diff --git a/tests/unit/plugins/relay/api/test-relay-api-protocol.cpp b/tests/unit/plugins/relay/api/test-relay-api-protocol.cpp
index ac7eed8ed..3b68b347e 100644
--- a/tests/unit/plugins/relay/api/test-relay-api-protocol.cpp
+++ b/tests/unit/plugins/relay/api/test-relay-api-protocol.cpp
@@ -432,6 +432,7 @@ TEST(RelayApiProtocolWithClient, CbBuffers)
     WEE_CHECK_OBJ_NUM(1, json, "number");
     WEE_CHECK_OBJ_STR("formatted", json, "type");
     WEE_CHECK_OBJ_STRN("WeeChat", 7, json, "title");
+    WEE_CHECK_OBJ_STR("", json, "input_prompt");
     WEE_CHECK_OBJ_STR("", json, "input");
     WEE_CHECK_OBJ_NUM(0, json, "input_position");
     WEE_CHECK_OBJ_BOOL(0, json, "input_multiline");
@@ -442,6 +443,7 @@ TEST(RelayApiProtocolWithClient, CbBuffers)
     WEE_CHECK_OBJ_STR("weechat", json_var, "name");
 
     /* get one buffer by name */
+    gui_buffer_set (gui_buffers, "input_prompt", "test_prompt");
     gui_buffer_set (gui_buffers, "input", "test");
     gui_buffer_set (gui_buffers, "input_pos", "4");
     gui_buffer_set (gui_buffers, "input_multiline", "1");
@@ -456,6 +458,7 @@ TEST(RelayApiProtocolWithClient, CbBuffers)
     WEE_CHECK_OBJ_NUM(1, json, "number");
     WEE_CHECK_OBJ_STR("formatted", json, "type");
     WEE_CHECK_OBJ_STRN("WeeChat", 7, json, "title");
+    WEE_CHECK_OBJ_STR("test_prompt", json, "input_prompt");
     WEE_CHECK_OBJ_STR("test", json, "input");
     WEE_CHECK_OBJ_NUM(4, json, "input_position");
     WEE_CHECK_OBJ_BOOL(1, json, "input_multiline");
@@ -464,6 +467,7 @@ TEST(RelayApiProtocolWithClient, CbBuffers)
     CHECK(cJSON_IsObject (json_var));
     WEE_CHECK_OBJ_STR("core", json_var, "plugin");
     WEE_CHECK_OBJ_STR("weechat", json_var, "name");
+    gui_buffer_set (gui_buffers, "input_prompt", "");
     gui_buffer_set (gui_buffers, "input", "");
     gui_buffer_set (gui_buffers, "input_multiline", "0");
 
@@ -481,6 +485,7 @@ TEST(RelayApiProtocolWithClient, CbBuffers)
     WEE_CHECK_OBJ_NUM(1, json, "number");
     WEE_CHECK_OBJ_STR("formatted", json, "type");
     WEE_CHECK_OBJ_STRN("WeeChat", 7, json, "title");
+    WEE_CHECK_OBJ_STR("", json, "input_prompt");
     WEE_CHECK_OBJ_STR("", json, "input");
     WEE_CHECK_OBJ_NUM(0, json, "input_position");
     WEE_CHECK_OBJ_BOOL(0, json, "input_multiline");