diff --git a/var/spack/repos/builtin/packages/conduit/package.py b/var/spack/repos/builtin/packages/conduit/package.py
index d8fa4fa2596..67d3256be80 100644
--- a/var/spack/repos/builtin/packages/conduit/package.py
+++ b/var/spack/repos/builtin/packages/conduit/package.py
@@ -121,6 +121,9 @@ class Conduit(CMakePackage):
     depends_on("hdf5@1.8.19:1.8.999~shared~cxx", when="+hdf5+hdf5_compat~shared")
     depends_on("hdf5~cxx", when="+hdf5~hdf5_compat+shared")
     depends_on("hdf5~shared~cxx", when="+hdf5~hdf5_compat~shared")
+    # we need to hand this to conduit so it can properly
+    # handle downstream linking of zlib reqed by hdf5
+    depends_on("zlib", when="+hdf5")
 
     ###############
     # Silo
@@ -514,6 +517,7 @@ def hostconfig(self, spec, prefix):
 
         if "+hdf5" in spec:
             cfg.write(cmake_cache_entry("HDF5_DIR", spec['hdf5'].prefix))
+            cfg.write(cmake_cache_entry("ZLIB_DIR", spec['zlib'].prefix))
         else:
             cfg.write("# hdf5 not built by spack \n")