diff --git a/var/spack/repos/builtin/packages/portage/package.py b/var/spack/repos/builtin/packages/portage/package.py
index 91fc5fa4dc5..283fcef39a1 100644
--- a/var/spack/repos/builtin/packages/portage/package.py
+++ b/var/spack/repos/builtin/packages/portage/package.py
@@ -51,7 +51,7 @@ def cmake_args(self):
         else:
             options.append('-DENABLE_MPI=OFF')
 
-        options.append("-DLAPACKE_LIBRARIES=" +
+        options.append("-DLAPACKE_LIBRARY=" +
                        self.spec["lapack"].libs.joined(";"))
 
         return options