diff --git a/libs/community/langchain_community/vectorstores/opensearch_vector_search.py b/libs/community/langchain_community/vectorstores/opensearch_vector_search.py
index 99ece00e7a69c..685bf33d328f3 100644
--- a/libs/community/langchain_community/vectorstores/opensearch_vector_search.py
+++ b/libs/community/langchain_community/vectorstores/opensearch_vector_search.py
@@ -81,14 +81,16 @@ def _validate_aoss_with_engines(is_aoss: bool, engine: str) -> None:
 
 
 def _is_aoss_enabled(http_auth: Any) -> bool:
-    """Check if the service is http_auth is set as `aoss`."""
-    if (
-        http_auth is not None
-        and hasattr(http_auth, "service")
-        and http_auth.service == "aoss"
-    ):
-        return True
-    return False
+    """Check if service attribute of http_auth is set to `aoss`."""
+    if http_auth is not None:
+        if hasattr(http_auth, "service") and http_auth.service == "aoss":
+            return True
+        elif hasattr(http_auth, "signer") and http_auth.signer.service == "aoss":
+            return True
+        else:
+            return False
+    else:
+        return False
 
 
 def _bulk_ingest_embeddings(
diff --git a/libs/community/pyproject.toml b/libs/community/pyproject.toml
index f05d6580af262..7532ea747f589 100644
--- a/libs/community/pyproject.toml
+++ b/libs/community/pyproject.toml
@@ -83,6 +83,8 @@ msal = {version = "^1.25.0", optional = true}
 databricks-vectorsearch = {version = "^0.21", optional = true}
 dgml-utils = {version = "^0.3.0", optional = true}
 datasets = {version = "^2.15.0", optional = true}
+requests-aws4auth = {version = "^1.2.3", optional = true}
+opensearch-py = {version = "^2.4.2", optional = true}
 
 [tool.poetry.group.test]
 optional = true
@@ -241,6 +243,8 @@ extended_testing = [
  "databricks-vectorsearch",
  "dgml-utils",
  "cohere",
+ "opensearch-py",
+ "requests-aws4auth",
 ]
 
 [tool.ruff]
diff --git a/libs/community/tests/unit_tests/vectorstores/test_opensearch_vector_search.py b/libs/community/tests/unit_tests/vectorstores/test_opensearch_vector_search.py
new file mode 100644
index 0000000000000..6dd6bbc5e9ce5
--- /dev/null
+++ b/libs/community/tests/unit_tests/vectorstores/test_opensearch_vector_search.py
@@ -0,0 +1,56 @@
+import pytest
+from pytest_mock import MockerFixture
+
+from langchain_community.embeddings import FakeEmbeddings
+from langchain_community.vectorstores.opensearch_vector_search import (
+    OpenSearchVectorSearch,
+)
+
+
+@pytest.mark.requires("opensearchpy")
+@pytest.mark.parametrize(["service", "expected"], [("aoss", True), ("es", False)])
+def test_detect_aoss_using_signer_auth(
+    mocker: MockerFixture, service: str, expected: bool
+) -> None:
+    from opensearchpy import RequestsAWSV4SignerAuth
+
+    mocker.patch.object(RequestsAWSV4SignerAuth, "_sign_request")
+    http_auth = RequestsAWSV4SignerAuth(
+        credentials="credentials", region="eu-central-1", service=service
+    )
+    database = OpenSearchVectorSearch(
+        opensearch_url="http://localhost:9200",
+        index_name="test",
+        embedding_function=FakeEmbeddings(size=42),
+        http_auth=http_auth,
+    )
+
+    assert database.is_aoss == expected
+
+
+@pytest.mark.requires("opensearchpy")
+@pytest.mark.requires("requests_aws4auth")
+@pytest.mark.parametrize(["service", "expected"], [("aoss", True), ("es", False)])
+def test_detect_aoss_using_aws4auth(service: str, expected: bool) -> None:
+    from requests_aws4auth import AWS4Auth
+
+    http_auth = AWS4Auth("access_key_id", "secret_access_key", "eu-central-1", service)
+    database = OpenSearchVectorSearch(
+        opensearch_url="http://localhost:9200",
+        index_name="test",
+        embedding_function=FakeEmbeddings(size=42),
+        http_auth=http_auth,
+    )
+
+    assert database.is_aoss == expected
+
+
+@pytest.mark.requires("opensearchpy")
+def test_detect_aoss_using_no_auth() -> None:
+    database = OpenSearchVectorSearch(
+        opensearch_url="http://localhost:9200",
+        index_name="test",
+        embedding_function=FakeEmbeddings(size=42),
+    )
+
+    assert database.is_aoss is False