diff --git a/test/test_snmp_conf_manager.cpp b/test/test_snmp_conf_manager.cpp
index f6111f7..6cb2a53 100644
--- a/test/test_snmp_conf_manager.cpp
+++ b/test/test_snmp_conf_manager.cpp
@@ -13,6 +13,8 @@
 {
 
 auto managerObjPath = "/xyz/openbmc_test/snmp/manager";
+using InvalidArgument =
+    sdbusplus::xyz::openbmc_project::Common::Error::InvalidArgument;
 
 class TestSNMPConfManager : public testing::Test
 {
@@ -103,6 +105,13 @@
     EXPECT_EQ(true, isClientExist("192.168.1.2"));
 }
 
+// Add duplicate SNMP client
+TEST_F(TestSNMPConfManager, AddDuplicateSNMPClient)
+{
+    createSNMPClient("192.168.1.1", 24);
+    EXPECT_THROW(createSNMPClient("192.168.1.1", 24), InvalidArgument);
+}
+
 // Delete SNMP client
 TEST_F(TestSNMPConfManager, DeleteSNMPClient)
 {