diff --git a/src/osx/slider_osx.cpp b/src/osx/slider_osx.cpp
index 6a7810e00c..512ff47894 100644
--- a/src/osx/slider_osx.cpp
+++ b/src/osx/slider_osx.cpp
@@ -22,7 +22,7 @@ BEGIN_EVENT_TABLE(wxSlider, wxControl)
 END_EVENT_TABLE()
 
  // The dimensions of the different styles of sliders (from Aqua document)
-#ifdef wxOSX_USE_COCOA
+#if wxOSX_USE_COCOA
     #define wxSLIDER_DIMENSIONACROSS_WITHTICKMARKS 28
     #define wxSLIDER_DIMENSIONACROSS_ARROW 21
 #else