Index: modules/control-utility/src/test/java/org/apache/ignite/util/ClientGridStartTest.java
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/modules/control-utility/src/test/java/org/apache/ignite/util/ClientGridStartTest.java b/modules/control-utility/src/test/java/org/apache/ignite/util/ClientGridStartTest.java
new file mode 100644
--- /dev/null	(date 1643026125706)
+++ b/modules/control-utility/src/test/java/org/apache/ignite/util/ClientGridStartTest.java	(date 1643026125706)
@@ -0,0 +1,47 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.ignite.util;
+
+import org.apache.ignite.configuration.IgniteConfiguration;
+import org.apache.ignite.testframework.junits.common.GridCommonAbstractTest;
+import org.junit.Test;
+
+/**
+ * Test
+ */
+public class ClientGridStartTest extends GridCommonAbstractTest {
+    /**
+     * {@inheritDoc}
+     */
+    @Override protected IgniteConfiguration getConfiguration(String igniteInstanceName) throws Exception {
+        IgniteConfiguration cfg = super.getConfiguration(igniteInstanceName);
+
+        cfg.setClientMode(false);
+
+        return cfg;
+    }
+
+    /**
+     * @throws Exception If failed.
+     */
+    @Test
+    public void test() throws Exception {
+        startGrids(1);
+        startClientGrid(42);
+    }
+}
\ No newline at end of file
Index: modules/core/src/test/java/org/apache/ignite/testframework/junits/GridAbstractTest.java
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/modules/core/src/test/java/org/apache/ignite/testframework/junits/GridAbstractTest.java b/modules/core/src/test/java/org/apache/ignite/testframework/junits/GridAbstractTest.java
--- a/modules/core/src/test/java/org/apache/ignite/testframework/junits/GridAbstractTest.java	(revision 831d6817a8888143cf31be3d30e309dd1a5d2856)
+++ b/modules/core/src/test/java/org/apache/ignite/testframework/junits/GridAbstractTest.java	(date 1643026053895)
@@ -1104,7 +1104,11 @@
         IgnitionEx.setClientMode(true);
 
         try {
-            return (IgniteEx)startGrid(igniteInstanceName, (GridSpringResourceContext)null);
+            IgniteEx ignite = (IgniteEx)startGrid(igniteInstanceName, (GridSpringResourceContext)null);
+
+            assert ignite.configuration().isClientMode();
+
+            return ignite;
         }
         finally {
             IgnitionEx.setClientMode(false);