diff --git a/microprofile/testing/mocking/src/main/java/io/helidon/microprofile/testing/mocking/MockBeansCdiExtension.java b/microprofile/testing/mocking/src/main/java/io/helidon/microprofile/testing/mocking/MockBeansCdiExtension.java
index eb68cc5c011..741e20fd198 100644
--- a/microprofile/testing/mocking/src/main/java/io/helidon/microprofile/testing/mocking/MockBeansCdiExtension.java
+++ b/microprofile/testing/mocking/src/main/java/io/helidon/microprofile/testing/mocking/MockBeansCdiExtension.java
@@ -68,23 +68,27 @@ private void processMockBeanParameters(List<? extends AnnotatedParameter<?>> par
         });
     }
 
-    void registerOtherBeans(@Observes AfterBeanDiscovery event, BeanManager beanManager) {
+    void registerMocks(@Observes AfterBeanDiscovery event, BeanManager beanManager) {
         // Register all mocks
         mocks.entrySet().forEach(entry -> {
+            Object eagerMock = Mockito.mock(entry.getKey(),
+                    Mockito.withSettings().defaultAnswer(entry.getValue().answer()));
             event.addBean()
                 .addType(entry.getKey())
                 .scope(ApplicationScoped.class)
                 .alternative(true)
                 .createWith(inst -> {
+                    Object mock;
                     Set<Bean<?>> beans = beanManager.getBeans(MockSettings.class);
                     if (!beans.isEmpty()) {
                         Bean<?> bean = beans.iterator().next();
                         MockSettings mockSettings = (MockSettings) beanManager.getReference(bean, MockSettings.class,
                                 beanManager.createCreationalContext(null));
-                        return Mockito.mock(entry.getKey(), mockSettings);
+                        mock = Mockito.mock(entry.getKey(), mockSettings);
                     } else {
-                        return Mockito.mock(entry.getKey(), Mockito.withSettings().defaultAnswer(entry.getValue().answer()));
+                        mock = eagerMock;
                     }
+                    return mock;
                 })
                 .priority(0);
         });
diff --git a/microprofile/tests/testing/junit5/src/test/java/io/helidon/microprofile/tests/testing/junit5/TestIssue9397.java b/microprofile/tests/testing/junit5/src/test/java/io/helidon/microprofile/tests/testing/junit5/TestIssue9397.java
new file mode 100644
index 00000000000..47cac4b80a5
--- /dev/null
+++ b/microprofile/tests/testing/junit5/src/test/java/io/helidon/microprofile/tests/testing/junit5/TestIssue9397.java
@@ -0,0 +1,49 @@
+/*
+ * Copyright (c) 2024 Oracle and/or its affiliates.
+ *
+ * Licensed 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 io.helidon.microprofile.tests.testing.junit5;
+
+import static org.hamcrest.CoreMatchers.is;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.mockito.ArgumentMatchers.anyString;
+
+import io.helidon.microprofile.testing.junit5.AddBean;
+import io.helidon.microprofile.testing.junit5.HelidonTest;
+import io.helidon.microprofile.testing.mocking.MockBean;
+
+import org.junit.jupiter.api.Test;
+import org.mockito.Mockito;
+
+@HelidonTest
+@AddBean(TestIssue9397.Service.class)
+class TestIssue9397 {
+
+    @MockBean
+    private Service service;
+
+    @Test
+    void testArgumentMatcher() {
+        Mockito.when(service.test(anyString())).thenReturn("Mocked");
+        assertThat(service.test("something"), is("Mocked"));
+    }
+
+    static class Service {
+
+        String test(String test) {
+            return test;
+        }
+    }
+}
diff --git a/microprofile/tests/testing/testng/src/test/java/io/helidon/microprofile/tests/testing/testng/TestIssue9397.java b/microprofile/tests/testing/testng/src/test/java/io/helidon/microprofile/tests/testing/testng/TestIssue9397.java
new file mode 100644
index 00000000000..94cf1df0021
--- /dev/null
+++ b/microprofile/tests/testing/testng/src/test/java/io/helidon/microprofile/tests/testing/testng/TestIssue9397.java
@@ -0,0 +1,50 @@
+/*
+ * Copyright (c) 2024 Oracle and/or its affiliates.
+ *
+ * Licensed 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 io.helidon.microprofile.tests.testing.testng;
+
+import static org.hamcrest.CoreMatchers.is;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.mockito.ArgumentMatchers.anyString;
+
+import jakarta.inject.Inject;
+
+import io.helidon.microprofile.testing.mocking.MockBean;
+import io.helidon.microprofile.testing.testng.HelidonTest;
+
+import org.mockito.Mockito;
+import org.testng.annotations.Test;
+
+@HelidonTest
+class TestIssue9397 {
+
+    @MockBean
+    @Inject
+    private Service service;
+
+    @Test
+    void testArgumentMatcher() {
+        Mockito.when(service.test(anyString())).thenReturn("Mocked");
+        assertThat(service.test("something"), is("Mocked"));
+    }
+
+    static class Service {
+
+        String test(String test) {
+            return test;
+        }
+    }
+}