diff --git a/deps/CMakeLists.txt b/deps/CMakeLists.txt
index 06ab0fa652..74bf6eb53e 100644
--- a/deps/CMakeLists.txt
+++ b/deps/CMakeLists.txt
@@ -152,8 +152,10 @@ include(MPFR/MPFR.cmake)
 include(CGAL/CGAL.cmake)
 include(wxWidgets/wxWidgets.cmake)
 
-add_dependencies(dep_blosc ${ZLIB_PKG})
-add_dependencies(dep_openexr ${ZLIB_PKG})
+if (ZLIB_PKG)
+    add_dependencies(dep_blosc ${ZLIB_PKG})
+    add_dependencies(dep_openexr ${ZLIB_PKG})
+endif ()
 
 if (MSVC)