diff --git a/Utilities/Release/dashmacmini2_release.cmake b/Utilities/Release/dashmacmini2_release.cmake
index 6a27119f9..ba82aab7f 100644
--- a/Utilities/Release/dashmacmini2_release.cmake
+++ b/Utilities/Release/dashmacmini2_release.cmake
@@ -6,6 +6,7 @@ set(HOST dashmacmini2)
 set(MAKE_PROGRAM "make")
 set(MAKE "${MAKE_PROGRAM} -j2")
 set(CPACK_BINARY_GENERATORS "DragNDrop TGZ TZ")
+set(CPACK_DMG_FORMAT "UDBZ") #build using bzip2 for smaller package size
 set(INITIAL_CACHE "
 CMAKE_BUILD_TYPE:STRING=Release
 CMAKE_OSX_ARCHITECTURES:STRING=ppc;i386
diff --git a/Utilities/Release/dashmacmini5_release.cmake b/Utilities/Release/dashmacmini5_release.cmake
index 16a30b3b6..d332816c2 100644
--- a/Utilities/Release/dashmacmini5_release.cmake
+++ b/Utilities/Release/dashmacmini5_release.cmake
@@ -7,6 +7,7 @@ set(MAKE_PROGRAM "make")
 set(MAKE "${MAKE_PROGRAM} -j5")
 set(CPACK_BINARY_GENERATORS "DragNDrop TGZ TZ")
 set(CPACK_SOURCE_GENERATORS "TGZ TZ")
+set(CPACK_DMG_FORMAT "UDBZ") #build using bzip2 for smaller package size
 set(INITIAL_CACHE "
 CMAKE_USE_OPENSSL:BOOL=ON
 OPENSSL_CRYPTO_LIBRARY:FILEPATH=/Users/kitware/openssl-1.0.1g-install/lib/libcrypto.a