diff --git a/modules/juce_product_unlocking/juce_product_unlocking.cpp b/modules/juce_product_unlocking/juce_product_unlocking.cpp
index b0bf797da8..cbf017067a 100644
--- a/modules/juce_product_unlocking/juce_product_unlocking.cpp
+++ b/modules/juce_product_unlocking/juce_product_unlocking.cpp
@@ -45,9 +45,8 @@
 #define JUCE_CORE_INCLUDE_OBJC_HELPERS   1
 #define JUCE_CORE_INCLUDE_NATIVE_HEADERS 1
 
-// Set this flag to 1 to use test servers on iOS
-#ifndef JUCE_IN_APP_PURCHASES_USE_SANDBOX_ENVIRONMENT
-    #define JUCE_IN_APP_PURCHASES_USE_SANDBOX_ENVIRONMENT 0
+#ifdef JUCE_IN_APP_PURCHASES_USE_SANDBOX_ENVIRONMENT
+ JUCE_COMPILER_WARNING ("JUCE_IN_APP_PURCHASES_USE_SANDBOX_ENVIRONMENT is no longer supported")
 #endif
 
 #include "juce_product_unlocking.h"