diff --git a/src/main/java/io/appium/java_client/service/local/AppiumServiceBuilder.java b/src/main/java/io/appium/java_client/service/local/AppiumServiceBuilder.java
index cf1e5ee89..0196579c2 100644
--- a/src/main/java/io/appium/java_client/service/local/AppiumServiceBuilder.java
+++ b/src/main/java/io/appium/java_client/service/local/AppiumServiceBuilder.java
@@ -203,7 +203,7 @@ public AppiumServiceBuilder withArgument(ServerArgument argument) {
      * @return the self-reference.
      */
     public AppiumServiceBuilder withArgument(ServerArgument argument, String value) {
-        String argName = argument.getArgument().trim().toLowerCase();
+        String argName = argument.getArgument();
         switch (argName) {
             case "--port":
             case "-p":