diff --git a/var/spack/repos/builtin/packages/conduit/package.py b/var/spack/repos/builtin/packages/conduit/package.py
index b8b23bccbee..8481ddce82f 100644
--- a/var/spack/repos/builtin/packages/conduit/package.py
+++ b/var/spack/repos/builtin/packages/conduit/package.py
@@ -469,7 +469,7 @@ def create_host_config(self, spec, prefix, py_site_pkgs_dir=None):
             # use those for mpi wrappers, b/c  spec['mpi'].mpicxx
             # etc make return the spack compiler wrappers
             # which can trip up mpi detection in CMake 3.14
-            if cpp_compiler == "CC":
+            if spec['mpi'].mpicc == spack_cc:
                 mpicc_path = "cc"
                 mpicxx_path = "CC"
                 mpifc_path = "ftn"
diff --git a/var/spack/repos/builtin/packages/hydrogen/package.py b/var/spack/repos/builtin/packages/hydrogen/package.py
index c28d0872d90..449fe046dc5 100644
--- a/var/spack/repos/builtin/packages/hydrogen/package.py
+++ b/var/spack/repos/builtin/packages/hydrogen/package.py
@@ -117,9 +117,6 @@ def cmake_args(self):
 
         args = [
             '-DCMAKE_INSTALL_MESSAGE:STRING=LAZY',
-            '-DCMAKE_C_COMPILER=%s' % spec['mpi'].mpicc,
-            '-DCMAKE_CXX_COMPILER=%s' % spec['mpi'].mpicxx,
-            '-DCMAKE_Fortran_COMPILER=%s' % spec['mpi'].mpifc,
             '-DBUILD_SHARED_LIBS:BOOL=%s'      % ('+shared' in spec),
             '-DHydrogen_ENABLE_OPENMP:BOOL=%s'       % ('+hybrid' in spec),
             '-DHydrogen_ENABLE_QUADMATH:BOOL=%s'     % ('+quad' in spec),