diff --git a/sdk/cosmos/azure-cosmos-tests/src/test/java/com/azure/cosmos/implementation/RxDocumentClientImplTest.java b/sdk/cosmos/azure-cosmos-tests/src/test/java/com/azure/cosmos/implementation/RxDocumentClientImplTest.java
index 7ea3c5b87322f..2c6411334ad41 100644
--- a/sdk/cosmos/azure-cosmos-tests/src/test/java/com/azure/cosmos/implementation/RxDocumentClientImplTest.java
+++ b/sdk/cosmos/azure-cosmos-tests/src/test/java/com/azure/cosmos/implementation/RxDocumentClientImplTest.java
@@ -10,6 +10,7 @@
 import com.azure.cosmos.CosmosDiagnostics;
 import com.azure.cosmos.CosmosEndToEndOperationLatencyPolicyConfig;
 import com.azure.cosmos.CosmosItemSerializer;
+import com.azure.cosmos.Http2ConnectionConfig;
 import com.azure.cosmos.SessionRetryOptions;
 import com.azure.cosmos.implementation.apachecommons.lang.tuple.ImmutablePair;
 import com.azure.cosmos.implementation.caches.RxClientCollectionCache;
@@ -179,6 +180,7 @@ public void readMany() {
         Mockito.when(this.connectionPolicyMock.getMaxConnectionPoolSize()).thenReturn(dummyInt);
         Mockito.when(this.connectionPolicyMock.getProxy()).thenReturn(dummyProxyOptions);
         Mockito.when(this.connectionPolicyMock.getHttpNetworkRequestTimeout()).thenReturn(dummyDuration);
+        Mockito.when(this.connectionPolicyMock.getHttp2ConnectionConfig()).thenReturn(new Http2ConnectionConfig());
 
         httpClientMock
             .when(() -> HttpClient.createFixed(Mockito.any(HttpClientConfig.class)))
diff --git a/sdk/cosmos/azure-cosmos/src/main/java/com/azure/cosmos/implementation/http/HttpClientConfig.java b/sdk/cosmos/azure-cosmos/src/main/java/com/azure/cosmos/implementation/http/HttpClientConfig.java
index d7a25196a55c5..f556e012426ea 100644
--- a/sdk/cosmos/azure-cosmos/src/main/java/com/azure/cosmos/implementation/http/HttpClientConfig.java
+++ b/sdk/cosmos/azure-cosmos/src/main/java/com/azure/cosmos/implementation/http/HttpClientConfig.java
@@ -172,6 +172,6 @@ public String toDiagnosticsString() {
             maxIdleConnectionTimeout,
             connectionAcquireTimeout,
             proxy != null,
-            http2ConnectionConfig.toDiagnosticsString());
+            http2ConnectionConfig == null ? null : http2ConnectionConfig.toDiagnosticsString());
     }
 }