diff --git a/tests/__init__.py b/tests/__init__.py
index 9d67e99..cfa1353 100644
--- a/tests/__init__.py
+++ b/tests/__init__.py
@@ -83,6 +83,9 @@ class GrayTest:
         ref = load_unit(self.reference / 'fort.7')
         cand = load_unit(self.candidate / 'fort.7')
 
+        if ref.size == 0 or cand.size == 0:
+            raise unittest.SkipTest("ECCD results not available")
+
         # precision as number of decimal places
         prec = defaultdict(lambda: 3, [
             ('dPdVp', -2), ('dPdVmx', -2),