diff --git a/Dockerfile b/Dockerfile
index 754a655..ccf3c76 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -7,9 +7,15 @@ FROM docker.io/node:16 AS builder
 # Set working directory
 WORKDIR /app
 
+
+# Filled with placeholders, later changed and managed
+# by the substitute_environment_variables.sh file
 ENV SAFETWITCH_BACKEND_DOMAIN SAFETWITCH_BACKEND_DOMAIN_PLACEHOLDER
 ENV SAFETWITCH_INSTANCE_DOMAIN SAFETWITCH_INSTANCE_DOMAIN_PLACEHOLDER
 ENV SAFETWITCH_HTTPS SAFETWITCH_HTTPS_PLACEHOLDER
+ENV SAFETWITCH_DEFAULT_LOCALE SAFETWITCH_DEFAULT_LOCALE_PLACEHOLDER
+ENV SAFETWITCH_FALLBACK_LOCALE SAFETWITCH_FALLBACK_LOCALE_PLACEHOLDER
+ENV SAFETWITCH_DEFAULT_THEME SAFETWITCH_DEFAULT_THEME_PLACEHOLDER
 # Copy all files from current directory to working dir in image
 COPY . .
 # install node modules and build assets
@@ -23,7 +29,7 @@ RUN mkdir /app
 # Copy static assets from builder stage
 COPY --from=builder /app/dist /app
 # Containers run nginx with global directives and daemon off
-EXPOSE 80
+EXPOSE 8280
 
 # Overriding the default NGINX container behavior
 COPY ./substitute_environment_variables.sh ./substitute_environment_variables.sh
diff --git a/src/i18n.ts b/src/i18n.ts
index d1ee724..810ba07 100644
--- a/src/i18n.ts
+++ b/src/i18n.ts
@@ -17,8 +17,8 @@ import zh_Hans from '@/locales/zh_Hans.json'
 
 export default createI18n({
   legacy: false,
-  locale: import.meta.env.VUE_APP_I18N_LOCALE || 'en-US',
-  fallbackLocale: import.meta.env.VUE_APP_I18N_FALLBACK_LOCALE || 'en-US',
+  locale: import.meta.env.SAFETWITCH_DEFAULT_LOCALE || 'en-US',
+  fallbackLocale: import.meta.env.SAFETWITCH_FALLBACK_LOCALE || 'en-US',
   globalInjection: true,
   messages: {
     'en-US': en,
diff --git a/substitute_environment_variables.sh b/substitute_environment_variables.sh
index 1d2ee87..e545fb8 100755
--- a/substitute_environment_variables.sh
+++ b/substitute_environment_variables.sh
@@ -10,7 +10,9 @@ else
   export SAFETWITCH_BACKEND_DOMAIN_PLACEHOLDER=SAFETWITCH_BACKEND_DOMAIN_PLACEHOLDER
   export SAFETWITCH_INSTANCE_DOMAIN_PLACEHOLDER=SAFETWITCH_INSTANCE_DOMAIN_PLACEHOLDER
   export SAFETWITCH_HTTPS_PLACEHOLDER=SAFETWITCH_HTTPS_PLACEHOLDER
-  export SAFETWITCH_DEFAULT_THEME_PLACEHOLDER=light
+  export SAFETWITCH_DEFAULT_THEME_PLACEHOLDER=SAFETWITCH_DEFAULT_THEME_PLACEHOLDER
+  export SAFETWITCH_DEFAULT_LOCALE_PLACEHOLDER=SAFETWITCH_DEFAULT_LOCALE_PLACEHOLDER
+  export SAFETWITCH_FALLBACK_LOCALE_PLACEHOLDER=SAFETWITCH_FALLBACK_LOCALE_PLACEHOLDER
 fi
 
 # Replace env vars in files served by NGINX
@@ -20,6 +22,8 @@ do
   sed -i 's|'${SAFETWITCH_INSTANCE_DOMAIN_PLACEHOLDER}'|'${SAFETWITCH_INSTANCE_DOMAIN}'|g' $file
   sed -i 's|'${SAFETWITCH_HTTPS_PLACEHOLDER}'|'${SAFETWITCH_HTTPS}'|g' $file
   sed -i 's|'${SAFETWITCH_DEFAULT_THEME_PLACEHOLDER}'|'${SAFETWITCH_DEFAULT_THEME}'|g' $file
+  sed -i 's|'${SAFETWITCH_DEFAULT_LOCALE_PLACEHOLDER}'|'${SAFETWITCH_DEFAULT_LOCALE}'|g' $file
+  sed -i 's|'${SAFETWITCH_FALLBACK_LOCALE_PLACEHOLDER}'|'${SAFETWITCH_FALLBACK_LOCALE}'|g' $file
   # Your other variables here...
 done
 
@@ -28,6 +32,8 @@ echo -e "SAFETWITCH_BACKEND_DOMAIN_PLACEHOLDER=${SAFETWITCH_BACKEND_DOMAIN}" > .
 echo -e "SAFETWITCH_INSTANCE_DOMAIN_PLACEHOLDER=${SAFETWITCH_INSTANCE_DOMAIN}" >> .env.old
 echo -e "SAFETWITCH_HTTPS_PLACEHOLDER=${SAFETWITCH_HTTPS}" >> .env.old
 echo -e "SAFETWITCH_DEFAULT_THEME_PLACEHOLDER=${SAFETWITCH_DEFAULT_THEME}" >> .env.old
+echo -e "SAFETWITCH_DEFAULT_LOCALE_PLACEHOLDER=${SAFETWITCH_DEFAULT_LOCALE}" >> .env.old
+echo -e "SAFETWITCH_FALLBACK_LOCALE_PLACEHOLDER=${SAFETWITCH_FALLBACK_LOCALE}" >> .env.old
 
 # Starting NGINX
 nginx -g 'daemon off;'
\ No newline at end of file