diff --git a/mobile/examples/basic_usage/model/requirements.txt b/mobile/examples/basic_usage/model/requirements.txt
index aa4fc09ee..41b1d1d65 100644
--- a/mobile/examples/basic_usage/model/requirements.txt
+++ b/mobile/examples/basic_usage/model/requirements.txt
@@ -1,2 +1,3 @@
 onnx==1.10.0
 onnxruntime==1.10.0
+protobuf==3.20.1
diff --git a/mobile/examples/object_detection/ios/ORTObjectDetection/prepare_model.requirements.txt b/mobile/examples/object_detection/ios/ORTObjectDetection/prepare_model.requirements.txt
index e18772160..e650e2547 100644
--- a/mobile/examples/object_detection/ios/ORTObjectDetection/prepare_model.requirements.txt
+++ b/mobile/examples/object_detection/ios/ORTObjectDetection/prepare_model.requirements.txt
@@ -1,4 +1,5 @@
 onnx==1.10.0
 onnxruntime==1.10.0
+protobuf==3.20.1
 tensorflow==2.6.3
 tf2onnx==1.9.3