diff --git a/modules/juce_core/system/juce_PlatformDefs.h b/modules/juce_core/system/juce_PlatformDefs.h
index 17b4d90433..bb80b3749f 100644
--- a/modules/juce_core/system/juce_PlatformDefs.h
+++ b/modules/juce_core/system/juce_PlatformDefs.h
@@ -305,7 +305,9 @@ namespace juce
   #define JUCE_COMPILER_SUPPORTS_MOVE_SEMANTICS 1
  #endif
 
- #define JUCE_COMPILER_SUPPORTS_ARC 1
+ #ifndef JUCE_COMPILER_SUPPORTS_ARC
+  #define JUCE_COMPILER_SUPPORTS_ARC 1
+ #endif
 #endif
 
 #if defined (_MSC_VER) && _MSC_VER >= 1600