diff --git a/apps/emqx_bridge_greptimedb/src/emqx_bridge_greptimedb.erl b/apps/emqx_bridge_greptimedb/src/emqx_bridge_greptimedb.erl
index d63103e2e..f5ae714d7 100644
--- a/apps/emqx_bridge_greptimedb/src/emqx_bridge_greptimedb.erl
+++ b/apps/emqx_bridge_greptimedb/src/emqx_bridge_greptimedb.erl
@@ -126,7 +126,7 @@ desc(_) ->
     undefined.
 
 write_syntax(type) ->
-    emqx_bridge_influxdb:write_syntax();
+    emqx_bridge_influxdb:write_syntax_type();
 write_syntax(required) ->
     true;
 write_syntax(validator) ->
diff --git a/apps/emqx_bridge_influxdb/src/emqx_bridge_influxdb.erl b/apps/emqx_bridge_influxdb/src/emqx_bridge_influxdb.erl
index 47eeecb4e..acb295752 100644
--- a/apps/emqx_bridge_influxdb/src/emqx_bridge_influxdb.erl
+++ b/apps/emqx_bridge_influxdb/src/emqx_bridge_influxdb.erl
@@ -11,7 +11,8 @@
 -import(hoconsc, [mk/2, enum/1, ref/2]).
 
 -export([
-    conn_bridge_examples/1
+    conn_bridge_examples/1,
+    write_syntax_type/0
 ]).
 
 -export([
@@ -29,6 +30,9 @@
 %% -------------------------------------------------------------------------------------------------
 %% api
 
+write_syntax_type() ->
+    typerefl:alias("string", write_syntax()).
+
 conn_bridge_examples(Method) ->
     [
         #{
@@ -154,7 +158,7 @@ desc(_) ->
     undefined.
 
 write_syntax(type) ->
-    ?MODULE:write_syntax();
+    write_syntax_type();
 write_syntax(required) ->
     true;
 write_syntax(validator) ->