diff --git a/reframe/frontend/filters.py b/reframe/frontend/filters.py
index 9edf3ced3b..58c25f687c 100644
--- a/reframe/frontend/filters.py
+++ b/reframe/frontend/filters.py
@@ -110,13 +110,15 @@ def _fn(case):
 
 def have_gpu_only():
     def _fn(case):
-        return case.check.num_gpus_per_node > 0
+        # NOTE: This takes into account num_gpus_per_node being None
+        return case.check.num_gpus_per_node
 
     return _fn
 
 
 def have_cpu_only():
     def _fn(case):
-        return case.check.num_gpus_per_node == 0
+        # NOTE: This takes into account num_gpus_per_node being None
+        return not case.check.num_gpus_per_node
 
     return _fn
diff --git a/unittests/test_filters.py b/unittests/test_filters.py
index ff0fa39c06..f1dd63dfaa 100644
--- a/unittests/test_filters.py
+++ b/unittests/test_filters.py
@@ -35,7 +35,6 @@ class _X(rfm.RegressionTest):
                   maintainers=['A', 'B', 'C', 'D']),
         make_case(_X, alt_name='check2',
                   tags={'x', 'y', 'z'},
-                  num_gpus_per_node=0,
                   maintainers=['X', 'Y', 'Z']),
         make_case(_X, alt_name='check3',
                   tags={'a', 'z'},