diff --git a/runtimes/onnx-runtime/development/Dockerfile b/runtimes/onnx-runtime/development/Dockerfile
index e7c357ed54..75c7fe3457 100644
--- a/runtimes/onnx-runtime/development/Dockerfile
+++ b/runtimes/onnx-runtime/development/Dockerfile
@@ -3,11 +3,12 @@ FROM ubuntu:18.04
 # Disable interactive installation mode
 ENV DEBIAN_FRONTEND=noninteractive
 
-# Install Python dependencies
+# Install Python and locales dependencies
 RUN apt-get update && apt-get install -y \
     python3 \
     python3-dev \
-    python3-pip && \
+    python3-pip \
+    locales && \
     apt-get clean autoclean && apt-get autoremove -y
 
 RUN pip3 install --upgrade pip setuptools wheel
@@ -22,6 +23,9 @@ RUN pip3 install --no-cache-dir -r /root/setup/requirements_report.txt
 ############## ONNX Backend dependencies ###########
 ENV ONNX_BACKEND="onnxruntime.backend.backend"
 
+# Set locale which is required for StringNormalizer
+RUN locale-gen en_US.UTF-8 && update-locale LANG=en_US.UTF-8
+
 # Install dependencies
 RUN pip3 install onnx
 RUN pip3 install -i https://test.pypi.org/simple/ ort-nightly
diff --git a/runtimes/onnx-runtime/stable/Dockerfile b/runtimes/onnx-runtime/stable/Dockerfile
index 3131f611c6..a0a6a0451a 100644
--- a/runtimes/onnx-runtime/stable/Dockerfile
+++ b/runtimes/onnx-runtime/stable/Dockerfile
@@ -3,11 +3,12 @@ FROM ubuntu:18.04
 # Disable interactive installation mode
 ENV DEBIAN_FRONTEND=noninteractive
 
-# Install Python dependencies
+# Install Python and locales dependencies
 RUN apt-get update && apt-get install -y \
     python3 \
     python3-dev \
-    python3-pip && \
+    python3-pip \
+    locales && \
     apt-get clean autoclean && apt-get autoremove -y
 
 RUN pip3 install --upgrade pip setuptools wheel
@@ -22,6 +23,9 @@ RUN pip3 install --no-cache-dir -r /root/setup/requirements_report.txt
 ############## ONNX Backend dependencies ###########
 ENV ONNX_BACKEND="onnxruntime.backend.backend"
 
+# Set locale which is required for StringNormalizer
+RUN locale-gen en_US.UTF-8 && update-locale LANG=en_US.UTF-8
+
 # Install dependencies
 RUN pip3 install onnx
 RUN pip3 install onnxruntime