diff --git a/dotnet/src/webdriver/Firefox/FirefoxDriverService.cs b/dotnet/src/webdriver/Firefox/FirefoxDriverService.cs
index 3d35057e69e64..419f998a251bb 100644
--- a/dotnet/src/webdriver/Firefox/FirefoxDriverService.cs
+++ b/dotnet/src/webdriver/Firefox/FirefoxDriverService.cs
@@ -177,7 +177,7 @@ protected override string CommandLineArguments
 
                 if (!string.IsNullOrEmpty(this.browserCommunicationHost))
                 {
-                    argsBuilder.AppendFormat(CultureInfo.InvariantCulture, " --marionette-host \"{0}\"", this.host);
+                    argsBuilder.AppendFormat(CultureInfo.InvariantCulture, " --marionette-host \"{0}\"", this.browserCommunicationHost);
                 }
 
                 if (this.Port > 0)