diff --git a/qt/widgets/common/src/DropEventHelper.cpp b/qt/widgets/common/src/DropEventHelper.cpp
index bab37ebd5f9d888baaddbbab9cef3080499ad897..8b2d7be08e96ac3cc1c2590bddcd4fae582609c7 100644
--- a/qt/widgets/common/src/DropEventHelper.cpp
+++ b/qt/widgets/common/src/DropEventHelper.cpp
@@ -8,7 +8,7 @@
 // Compile on OSX only.
 #if defined(__APPLE__)
 #include <CoreFoundation/CoreFoundation.h>
-#endif defined(__APPLE__)
+#endif // defined(__APPLE__)
 
 using namespace MantidQt::MantidWidgets;