diff --git a/README.md b/README.md
index 4c7b762e..bb95f1f1 100644
--- a/README.md
+++ b/README.md
@@ -240,6 +240,9 @@ There are some limitations to what characters you can use.
 | Name  | `0-9a-zA-Z_-`       |
 | Value | `0-9a-zA-Z_-:/=?.+` |
 
+Variables will be replaced in files with the following extensions:
+`.yml`, `.yaml`, `.txt`, `.cfg`, `.conf`, `.properties`.
+
 Here is a full example where we want to replace values inside a `database.yml`.
 
 ```yml
diff --git a/start-finalSetup05EnvVariables b/start-finalSetup05EnvVariables
index d1c44f49..532e28e4 100644
--- a/start-finalSetup05EnvVariables
+++ b/start-finalSetup05EnvVariables
@@ -1,15 +1,20 @@
 #!/bin/bash
 
-if [ "$REPLACE_ENV_VARIABLES" = "TRUE" ]; then
+if [ "${REPLACE_ENV_VARIABLES^^}" = "TRUE" ]; then
   echo "Replacing env variables in configs that match the prefix $ENV_VARIABLE_PREFIX..."
   while IFS='=' read -r name value ; do
     # check if name of env variable matches the prefix
     # sanity check environment variables to avoid code injections
-    if [[ "$name" = $ENV_VARIABLE_PREFIX* ]] && [[ $value =~ ^[0-9a-zA-Z_:/=?.+\-]*$ ]] && [[ $name =~ ^[0-9a-zA-Z_\-]*$ ]]; then
-        echo "Replacing $name with $value ..."
-        find /data/ -type f \( -name "*.yml" -or -name "*.yaml" -or -name "*.txt" -or -name "*.cfg" -or -name "*.properties" \) -exec sed -i 's#${'"$name"'}#'"$value"'#g' {} \;
+    if [[ "$name" = $ENV_VARIABLE_PREFIX* ]] \
+        && [[ $value =~ ^[0-9a-zA-Z_:/=?.+\-]*$ ]] \
+        && [[ $name =~ ^[0-9a-zA-Z_\-]*$ ]]; then
+      echo "Replacing $name with $value ..."
+      find /data/ -type f \
+          \( -name "*.yml" -or -name "*.yaml" -or -name "*.txt" -or -name "*.cfg" \
+          -or -name "*.conf" -or -name "*.properties" \) \
+          -exec sed -i 's#${'"$name"'}#'"$value"'#g' {} \;
     fi
   done < <(env)
 fi
 
-exec /start-minecraftFinalSetup $@
\ No newline at end of file
+exec /start-minecraftFinalSetup $@