diff --git a/tools/external_converter_v2/requirement.txt b/tools/external_converter_v2/requirement.txt
index 4397eacff..bb8680420 100644
--- a/tools/external_converter_v2/requirement.txt
+++ b/tools/external_converter_v2/requirement.txt
@@ -1,5 +1,5 @@
 pyyaml
-protobuf==3.1.0
+protobuf==3.18.3
 enum34
 numpy
 flask