diff --git a/vncviewer/CMakeLists.txt b/vncviewer/CMakeLists.txt
index 12cd8ae..524a007 100644
--- a/vncviewer/CMakeLists.txt
+++ b/vncviewer/CMakeLists.txt
@@ -23,7 +23,9 @@
 
 if(WIN32)
   set(VNCVIEWER_SOURCES ${VNCVIEWER_SOURCES} Win32PixelBuffer.cxx)
-elseif(NOT APPLE)
+elseif(APPLE)
+  set(VNCVIEWER_SOURCES ${VNCVIEWER_SOURCES} OSXPixelBuffer.cxx)
+else()
   set(VNCVIEWER_SOURCES ${VNCVIEWER_SOURCES} X11PixelBuffer.cxx)
 endif()