Index: interpreter/CMakeLists.txt
===================================================================
--- interpreter/CMakeLists.txt
+++ interpreter/CMakeLists.txt
@@ -21,6 +21,11 @@
   set(LLVM_ENABLE_CXX1Y ON CACHE BOOL "" FORCE)
 endif()
 
+if(builtin_zlib)
+  set(ZLIB_INCLUDE_DIR ${CMAKE_BINARY_DIR}/include CACHE BOOL "" FORCE)
+  set(ZLIB_LIBRARY ${CMAKE_BINARY_DIR}/lib/libZLIB.a CACHE BOOL "" FORCE)
+endif()
+
 # The llvm::ReverseIterate<bool>::value symbol from llvm's SmallPtrSet.h
 # somehow lands in our cling libraries on OS X and doesn't get hidden
 # by visibility-inlines-hidden, so we suddenly have a global weak symbol
Index: interpreter/llvm/src/cmake/config-ix.cmake
===================================================================
--- interpreter/llvm/src/cmake/config-ix.cmake
+++ interpreter/llvm/src/cmake/config-ix.cmake
@@ -131,7 +131,10 @@
 # like strlen, leading to false positives.
 if( NOT PURE_WINDOWS AND NOT LLVM_USE_SANITIZER MATCHES "Memory.*")
   if (LLVM_ENABLE_ZLIB)
-    check_library_exists(z compress2 "" HAVE_LIBZ)
+    find_package(ZLIB REQUIRED)
+    if (ZLIB_FOUND)
+      set(HAVE_LIBZ 1)
+    endif()
   else()
     set(HAVE_LIBZ 0)
   endif()
Index: interpreter/llvm/src/lib/Support/CMakeLists.txt
===================================================================
--- interpreter/llvm/src/lib/Support/CMakeLists.txt
+++ interpreter/llvm/src/lib/Support/CMakeLists.txt
@@ -22,7 +22,7 @@
   endif()
   set(system_libs ${system_libs} ${LLVM_PTHREAD_LIB})
   if ( LLVM_ENABLE_ZLIB AND HAVE_LIBZ )
-    set(system_libs ${system_libs} z)
+    set(system_libs ${system_libs} ${ZLIB_LIBRARY})
   endif()
   if( UNIX AND NOT (BEOS OR HAIKU) )
     set(system_libs ${system_libs} m)