diff --git a/lib/spack/spack/platforms/cray.py b/lib/spack/spack/platforms/cray.py
index ee3d40dc21e..6814f5be8e4 100644
--- a/lib/spack/spack/platforms/cray.py
+++ b/lib/spack/spack/platforms/cray.py
@@ -89,7 +89,7 @@ def setup_platform_environment(cls, pkg, env):
         """
         # Unload these modules to prevent any silent linking or unnecessary
         # I/O profiling in the case of darshan.
-        modules_to_unload = ["cray-mpich", "darshan", "cray-libsci"]
+        modules_to_unload = ["cray-mpich", "darshan", "cray-libsci", "altd"]
         for module in modules_to_unload:
             unload_module(module)