diff --git a/google/cloud/aiplatform/matching_engine/matching_engine_index_endpoint.py b/google/cloud/aiplatform/matching_engine/matching_engine_index_endpoint.py
index 94da9ac225..e2cb9efc2b 100644
--- a/google/cloud/aiplatform/matching_engine/matching_engine_index_endpoint.py
+++ b/google/cloud/aiplatform/matching_engine/matching_engine_index_endpoint.py
@@ -1865,7 +1865,7 @@ def find_neighbors(
                         dimensions=query.sparse_embedding_dimensions,
                     ),
                 )
-                if query.rrf_ranking_alpha:
+                if query.rrf_ranking_alpha is not None:
                     find_neighbors_query.rrf = (
                         gca_match_service_v1beta1.FindNeighborsRequest.Query.RRF(
                             alpha=query.rrf_ranking_alpha,
@@ -2200,7 +2200,7 @@ def match(
                         match_service_pb2.MatchRequest.RRF(
                             alpha=query.rrf_ranking_alpha,
                         )
-                        if query_is_hybrid and query.rrf_ranking_alpha
+                        if query_is_hybrid and query.rrf_ranking_alpha is not None
                         else None
                     ),
                 )
diff --git a/tests/unit/aiplatform/test_matching_engine_index_endpoint.py b/tests/unit/aiplatform/test_matching_engine_index_endpoint.py
index bb8d3642a8..15267f9d0c 100644
--- a/tests/unit/aiplatform/test_matching_engine_index_endpoint.py
+++ b/tests/unit/aiplatform/test_matching_engine_index_endpoint.py
@@ -258,6 +258,11 @@
         sparse_embedding_dimensions=[1, 2, 3],
         sparse_embedding_values=[0.1, 0.2, 0.3],
     ),
+    HybridQuery(
+        sparse_embedding_dimensions=[1, 2, 3],
+        sparse_embedding_values=[0.1, 0.2, 0.3],
+        rrf_ranking_alpha=0.0,  # Test edge case where alpha is 0
+    ),
 ]
 _TEST_NUM_NEIGHBOURS = 1
 _TEST_FILTER = [
@@ -1539,7 +1544,7 @@ def test_private_service_access_hybrid_search_match_queries(
                                 match_service_pb2.MatchRequest.RRF(
                                     alpha=_TEST_HYBRID_QUERIES[i].rrf_ranking_alpha,
                                 )
-                                if _TEST_HYBRID_QUERIES[i].rrf_ranking_alpha
+                                if _TEST_HYBRID_QUERIES[i].rrf_ranking_alpha is not None
                                 else None
                             ),
                         )
@@ -2093,6 +2098,27 @@ def test_index_public_endpoint_find_neighbors_queries(
                     approximate_neighbor_count=_TEST_APPROX_NUM_NEIGHBORS,
                     fraction_leaf_nodes_to_search_override=_TEST_FRACTION_LEAF_NODES_TO_SEARCH_OVERRIDE,
                 ),
+                gca_match_service_v1beta1.FindNeighborsRequest.Query(
+                    neighbor_count=_TEST_NUM_NEIGHBOURS,
+                    datapoint=gca_index_v1beta1.IndexDatapoint(
+                        restricts=[
+                            gca_index_v1beta1.IndexDatapoint.Restriction(
+                                namespace="class",
+                                allow_list=["token_1"],
+                                deny_list=["token_2"],
+                            )
+                        ],
+                        sparse_embedding=gca_index_v1beta1.IndexDatapoint.SparseEmbedding(
+                            values=[0.1, 0.2, 0.3], dimensions=[1, 2, 3]
+                        ),
+                    ),
+                    rrf=gca_match_service_v1beta1.FindNeighborsRequest.Query.RRF(
+                        alpha=0.0,
+                    ),
+                    per_crowding_attribute_neighbor_count=_TEST_PER_CROWDING_ATTRIBUTE_NUM_NEIGHBOURS,
+                    approximate_neighbor_count=_TEST_APPROX_NUM_NEIGHBORS,
+                    fraction_leaf_nodes_to_search_override=_TEST_FRACTION_LEAF_NODES_TO_SEARCH_OVERRIDE,
+                ),
             ],
             return_full_datapoint=_TEST_RETURN_FULL_DATAPOINT,
         )