diff --git a/var/spack/repos/builtin/packages/flux-core/package.py b/var/spack/repos/builtin/packages/flux-core/package.py
index 3d0e128ee43..016ca57c8b6 100644
--- a/var/spack/repos/builtin/packages/flux-core/package.py
+++ b/var/spack/repos/builtin/packages/flux-core/package.py
@@ -181,6 +181,12 @@ def setup_build_environment(self, env):
         env.append_path("LUA_PATH", "./?.lua", separator=";")
 
     def setup_run_environment(self, env):
+        # If this package is external, we expect the external provider to set things
+        # like LUA paths. So, we early return. If the package is not external,
+        # properly set these environment variables to make sure the user environment
+        # is configured correctly
+        if self.spec.external:
+            return
         env.prepend_path(
             "LUA_PATH", os.path.join(self.spec.prefix, self.lua_share_dir, "?.lua"), separator=";"
         )
diff --git a/var/spack/repos/builtin/packages/flux-sched/package.py b/var/spack/repos/builtin/packages/flux-sched/package.py
index 3f97fb0d769..d75024e041c 100644
--- a/var/spack/repos/builtin/packages/flux-sched/package.py
+++ b/var/spack/repos/builtin/packages/flux-sched/package.py
@@ -166,6 +166,12 @@ def lua_lib_dir(self):
         return os.path.join("lib", "lua", str(self.lua_version))
 
     def setup_run_environment(self, env):
+        # If this package is external, we expect the external provider to set
+        # things like LUA paths. So, we early return. If the package is not
+        # external, properly set these environment variables to make sure the
+        # user environment is configured correctly
+        if self.spec.external:
+            return
         env.prepend_path(
             "LUA_PATH", os.path.join(self.spec.prefix, self.lua_share_dir, "?.lua"), separator=";"
         )