diff --git a/lib/spack/spack/compilers/msvc.py b/lib/spack/spack/compilers/msvc.py
index 49f7582512a..cba2b6e41cc 100644
--- a/lib/spack/spack/compilers/msvc.py
+++ b/lib/spack/spack/compilers/msvc.py
@@ -323,7 +323,7 @@ def fc_version(cls, fc):
         fc_path[fc_ver] = fc
         if os.getenv("ONEAPI_ROOT"):
             try:
-                sps = spack.operating_systems.windows_os.WindowsOs.compiler_search_paths
+                sps = spack.operating_systems.windows_os.WindowsOs().compiler_search_paths
             except AttributeError:
                 raise SpackError("Windows compiler search paths not established")
             clp = spack.util.executable.which_string("cl", path=sps)