diff --git a/src/ragas/metrics/_factual_correctness.py b/src/ragas/metrics/_factual_correctness.py
index 0a88ae683..0d1f406ad 100644
--- a/src/ragas/metrics/_factual_correctness.py
+++ b/src/ragas/metrics/_factual_correctness.py
@@ -257,10 +257,10 @@ async def _single_turn_ascore(
         else:
             response_reference = np.array([])
 
+        response_reference = np.array(response_reference, dtype=bool)
         tp = sum(reference_response)
         fp = sum(~reference_response)
         if self.mode != "precision":
-            response_reference = np.array(response_reference, dtype=bool)
             fn = sum(~response_reference)
         else:
             fn = 0
diff --git a/src/ragas/testset/synthesizers/multi_hop/base.py b/src/ragas/testset/synthesizers/multi_hop/base.py
index 7c8a1c2f5..48b72ba7c 100644
--- a/src/ragas/testset/synthesizers/multi_hop/base.py
+++ b/src/ragas/testset/synthesizers/multi_hop/base.py
@@ -158,9 +158,10 @@ def convert_to_scenario(self, data: t.Dict[str, t.Any]) -> MultiHopScenario:
         )
 
     async def _generate_sample(
-        self, scenario: MultiHopScenario, callbacks: Callbacks
+        self, scenario: Scenario, callbacks: Callbacks
     ) -> SingleTurnSample:
-
+        if not isinstance(scenario, MultiHopScenario):
+            raise TypeError('scenario type should be MultiHopScenario')
         reference_context = self.make_contexts(scenario)
         prompt_input = QueryConditions(
             persona=scenario.persona,
diff --git a/src/ragas/testset/synthesizers/single_hop/base.py b/src/ragas/testset/synthesizers/single_hop/base.py
index 967ffaa2f..3a60a6dbc 100644
--- a/src/ragas/testset/synthesizers/single_hop/base.py
+++ b/src/ragas/testset/synthesizers/single_hop/base.py
@@ -119,9 +119,10 @@ def convert_to_scenario(self, data: t.Dict[str, t.Any]) -> SingleHopScenario:
         )
 
     async def _generate_sample(
-        self, scenario: SingleHopScenario, callbacks: Callbacks
+        self, scenario: Scenario, callbacks: Callbacks
     ) -> SingleTurnSample:
-
+        if not isinstance(scenario, SingleHopScenario):
+            raise TypeError('scenario type should be SingleHopScenario')
         reference_context = scenario.nodes[0].properties.get("page_content", "")
         prompt_input = QueryCondition(
             persona=scenario.persona,