diff --git a/var/spack/repos/builtin/packages/octopus/package.py b/var/spack/repos/builtin/packages/octopus/package.py
index 3ec5b6673a4..458cbebc64b 100644
--- a/var/spack/repos/builtin/packages/octopus/package.py
+++ b/var/spack/repos/builtin/packages/octopus/package.py
@@ -179,7 +179,10 @@ def configure_args(self):
             )
 
         if "+cgal" in spec:
+            # Boost is a dependency of CGAL, and is not picked up by the configure script
+            # unless specified explicitly with `--with-boost` option.
             args.append("--with-cgal-prefix=%s" % spec["cgal"].prefix)
+            args.append("--with-boost=%s" % spec["boost"].prefix)
 
         if "+likwid" in spec:
             args.append("--with-likwid-prefix=%s" % spec["likwid"].prefix)