diff --git a/utils/docker/Dockerfile.focal b/utils/docker/Dockerfile.focal
index 31690daa13..cd1d1d7c6e 100644
--- a/utils/docker/Dockerfile.focal
+++ b/utils/docker/Dockerfile.focal
@@ -4,6 +4,9 @@ ARG DEBIAN_FRONTEND=noninteractive
 ARG TZ=America/Los_Angeles
 ARG DOCKER_IMAGE_NAME_TEMPLATE="mcr.microsoft.com/playwright:v%version%-focal"
 
+ENV LANG=C.UTF-8
+ENV LC_ALL=C.UTF-8
+
 # === INSTALL Node.js ===
 
 RUN apt-get update && \
diff --git a/utils/docker/Dockerfile.jammy b/utils/docker/Dockerfile.jammy
index d7c70a729c..ff24c31c88 100644
--- a/utils/docker/Dockerfile.jammy
+++ b/utils/docker/Dockerfile.jammy
@@ -4,6 +4,9 @@ ARG DEBIAN_FRONTEND=noninteractive
 ARG TZ=America/Los_Angeles
 ARG DOCKER_IMAGE_NAME_TEMPLATE="mcr.microsoft.com/playwright:v%version%-jammy"
 
+ENV LANG=C.UTF-8
+ENV LC_ALL=C.UTF-8
+
 # === INSTALL Node.js ===
 
 RUN apt-get update && \