diff --git a/var/spack/repos/builtin/packages/ascent/package.py b/var/spack/repos/builtin/packages/ascent/package.py
index 593c0f2596..f5f5390820 100644
--- a/var/spack/repos/builtin/packages/ascent/package.py
+++ b/var/spack/repos/builtin/packages/ascent/package.py
@@ -303,7 +303,10 @@ def hostconfig(self):
         #######################
         c_compiler = env["SPACK_CC"]
         cpp_compiler = env["SPACK_CXX"]
-        f_compiler = env["SPACK_FC"]
+        if "+fortran" in spec:
+            f_compiler = env["SPACK_FC"]
+        else:
+            f_compiler = None
 
         #######################################################################
         # Directly fetch the names of the actual compilers to create a
diff --git a/var/spack/repos/builtin/packages/conduit/package.py b/var/spack/repos/builtin/packages/conduit/package.py
index dc824b8c92..ce6cee87ac 100644
--- a/var/spack/repos/builtin/packages/conduit/package.py
+++ b/var/spack/repos/builtin/packages/conduit/package.py
@@ -287,7 +287,10 @@ def hostconfig(self):
         #######################
         c_compiler = env["SPACK_CC"]
         cpp_compiler = env["SPACK_CXX"]
-        f_compiler = env["SPACK_FC"]
+        if "+fortran" in spec:
+            f_compiler = env["SPACK_FC"]
+        else:
+            f_compiler = None
 
         #######################################################################
         # Directly fetch the names of the actual compilers to create a