diff --git a/Superbuild/CMake/External_zlib.cmake b/Superbuild/CMake/External_zlib.cmake
index 9250917c22fc36cad192a54e8804d5fc90def3e9..3bc40c6bd95d86dd4c57b7eef28f9bf66d90b91f 100644
--- a/Superbuild/CMake/External_zlib.cmake
+++ b/Superbuild/CMake/External_zlib.cmake
@@ -2,26 +2,32 @@ message(STATUS "Setup Zlib ...")
 
 set(proj ZLIB)
 
-set(DEFAULT_USE_SYSTEM_ZLIB  ON)
-
-SETUP_SYSTEM_LIBRARY(PROJECT ${proj} DOC "  Use a system build of Zlib.")
+if(NOT __EXTERNAL_${proj}__)
+set(__EXTERNAL_${proj}__ 1)
 
 ADD_SYSTEM_PREFIX(PROJECT ${proj} CMAKE_ALIAS ZLIB_ROOT)
 
 if(USE_SYSTEM_ZLIB)
+  find_package(ZLIB REQUIRED)
   message(STATUS "  Using Zlib system version")
 else()
   SETUP_SUPERBUILD(PROJECT ${proj})
   
+  # declare dependencies
+  
+  INCLUDE_SUPERBUILD_DEPENDENCIES(${${proj}_DEPENDENCIES})
+  # set proj back to its original value
+  set(proj ZLIB)
+  
   # Try official release 1.2.8
   ExternalProject_Add(${proj}
     PREFIX ${proj}
     URL "http://sourceforge.net/projects/libpng/files/zlib/1.2.8/zlib-1.2.8.tar.gz/download"
     URL_MD5 44d667c142d7cda120332623eab69f40
     BINARY_DIR ${ZLIB_SB_BUILD_DIR}
-    INSTALL_DIR ${CMAKE_INSTALL_PREFIX}
+    INSTALL_DIR ${SB_INSTALL_PREFIX}
     CMAKE_CACHE_ARGS
-      -DCMAKE_INSTALL_PREFIX:PATH=${CMAKE_INSTALL_PREFIX}
+      -DCMAKE_INSTALL_PREFIX:PATH=${SB_INSTALL_PREFIX}
       -DCMAKE_BUILD_TYPE:STRING=Release
       #-DCMAKE_CXX_COMPILER:FILEPATH=${CMAKE_CXX_COMPILER}
       #-DCMAKE_C_COMPILER:FILEPATH=${CMAKE_C_COMPILER}
@@ -30,10 +36,21 @@ else()
   
     if(MSVC)
       ExternalProject_Add_Step(${proj} msvc_copy_hell
-        COMMAND ${CMAKE_COMMAND} -E copy ${ZLIB_SB_BUILD_DIR}/zlib.lib ${CMAKE_INSTALL_PREFIX}/lib/zdll.lib
+        COMMAND ${CMAKE_COMMAND} -E copy ${ZLIB_SB_BUILD_DIR}/zlib.lib ${SB_INSTALL_PREFIX}/lib/zdll.lib
         DEPENDEES install
       )  
     endif()
+    
+    set(ZLIB_INCLUDE_DIR ${SB_INSTALL_PREFIX}/include)
+    if(MSVC)
+      set(ZLIB_LIBRARY ${SB_INSTALL_PREFIX}/lib/zdll.lib)
+    elseif(APPLE)
+      set(ZLIB_LIBRARY ${SB_INSTALL_PREFIX}/lib/libz.dylib)
+    else()
+      set(ZLIB_LIBRARY ${SB_INSTALL_PREFIX}/lib/libz.so)
+    endif()
 
      message(STATUS "  Using zlib SuperBuild version")
 endif()
+
+endif()