diff --git a/tests/test_probabilist.cpp b/tests/test_probabilist.cpp
index 2a6dba7805a9794e601155ff478cd8a47123048e..26623457fe7c528c6839538cade53ab9505bd416 100644
--- a/tests/test_probabilist.cpp
+++ b/tests/test_probabilist.cpp
@@ -167,6 +167,6 @@ TEST(ProbabilistTests, TestMasks)
     // check results are identical
     for (int m = 0; m < metrics.size(); m++)
     {
-        EXPECT_TRUE(xt::allclose(metrics_masked[0], metrics_subset[0]));
+        EXPECT_TRUE(xt::allclose(metrics_masked[m], metrics_subset[m]));
     }
 }
\ No newline at end of file