diff --git a/testsuite/src/sparql_evaluator.rs b/testsuite/src/sparql_evaluator.rs
index 773792ab..a6e7d71a 100644
--- a/testsuite/src/sparql_evaluator.rs
+++ b/testsuite/src/sparql_evaluator.rs
@@ -445,6 +445,7 @@ fn are_query_results_isomorphic(
             },
         ) => {
             expected_variables == actual_variables
+                && expected_solutions.len() == actual_solutions.len()
                 && if *ordered {
                     expected_solutions.iter().zip(actual_solutions).all(
                         |(expected_solution, actual_solution)| {
diff --git a/testsuite/tests/sparql.rs b/testsuite/tests/sparql.rs
index c12cd26f..0b54bb87 100644
--- a/testsuite/tests/sparql.rs
+++ b/testsuite/tests/sparql.rs
@@ -60,7 +60,9 @@ fn sparql10_w3c_query_evaluation_testsuite() -> Result<()> {
         // We use XSD 1.1 equality on dates
         "http://www.w3.org/2001/sw/DataAccess/tests/data-r2/open-world/manifest#date-2",
         // We choose to simplify first the nested group patterns in OPTIONAL
-        "http://www.w3.org/2001/sw/DataAccess/tests/data-r2/optional-filter/manifest#dawg-optional-filter-005-not-simplified"
+        "http://www.w3.org/2001/sw/DataAccess/tests/data-r2/optional-filter/manifest#dawg-optional-filter-005-not-simplified",
+        // This test relies on naive iteration on the input file
+        "http://www.w3.org/2001/sw/DataAccess/tests/data-r2/reduced/manifest#reduced-2"
     ])
 }