diff --git a/src/model_converters/mmdnn_converter/requirements.txt b/src/model_converters/mmdnn_converter/requirements.txt
index d6691bab0..4fa9ed388 100644
--- a/src/model_converters/mmdnn_converter/requirements.txt
+++ b/src/model_converters/mmdnn_converter/requirements.txt
@@ -12,6 +12,6 @@ coremltools==2.1.0
 h5py==2.7.1
 torch==1.5.1
 torchvision==0.2.1
-onnx==1.4.1
+onnx==1.21.0
 onnx-tf==1.2.1
 mmdnn==0.3.1