diff --git a/cloud-sql/mysql/servlet/src/main/java/com/example/cloudsql/IndexServlet.java b/cloud-sql/mysql/servlet/src/main/java/com/example/cloudsql/IndexServlet.java
index 6551d57e899..06906010ad2 100644
--- a/cloud-sql/mysql/servlet/src/main/java/com/example/cloudsql/IndexServlet.java
+++ b/cloud-sql/mysql/servlet/src/main/java/com/example/cloudsql/IndexServlet.java
@@ -105,6 +105,8 @@ public void doPost(HttpServletRequest req, HttpServletResponse resp) throws IOEx
           .write(
               "Unable to successfully cast vote! Please check the application "
                   + "logs for more details.");
+      // Without this return the success response below overwrites the 500 and the error text.
+      return;
       // [END_EXCLUDE]
     }
     // [END cloud_sql_mysql_servlet_connection]
diff --git a/cloud-sql/mysql/servlet/src/test/java/com/example/cloudsql/TestIndexServletMysqlErrorResponse.java b/cloud-sql/mysql/servlet/src/test/java/com/example/cloudsql/TestIndexServletMysqlErrorResponse.java
new file mode 100644
index 00000000000..c19604e9c61
--- /dev/null
+++ b/cloud-sql/mysql/servlet/src/test/java/com/example/cloudsql/TestIndexServletMysqlErrorResponse.java
@@ -0,0 +1,70 @@
+/*
+ * Copyright 2024 Google LLC
+ *
+ * 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 com.example.cloudsql;
+
+import static com.google.common.truth.Truth.assertThat;
+import static org.mockito.ArgumentMatchers.anyInt;
+import static org.mockito.Mockito.doAnswer;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+import java.io.PrintWriter;
+import java.io.StringWriter;
+import java.sql.SQLException;
+import java.util.concurrent.atomic.AtomicInteger;
+import javax.servlet.ServletContext;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import javax.sql.DataSource;
+import org.junit.Test;
+
+/** Covers the doPost error path, which does not need a database. */
+public class TestIndexServletMysqlErrorResponse {
+
+  @Test
+  public void testFailedVoteIsNotReportedAsSuccess() throws Exception {
+    DataSource pool = mock(DataSource.class);
+    when(pool.getConnection()).thenThrow(new SQLException("connection refused"));
+
+    ServletContext context = mock(ServletContext.class);
+    when(context.getAttribute("my-pool")).thenReturn(pool);
+
+    HttpServletRequest request = mock(HttpServletRequest.class);
+    when(request.getServletContext()).thenReturn(context);
+    when(request.getParameter("team")).thenReturn("TABS");
+
+    StringWriter body = new StringWriter();
+    PrintWriter writer = new PrintWriter(body);
+    AtomicInteger status = new AtomicInteger();
+    HttpServletResponse response = mock(HttpServletResponse.class);
+    when(response.getWriter()).thenReturn(writer);
+    doAnswer(
+            invocation -> {
+              status.set(invocation.getArgument(0));
+              return null;
+            })
+        .when(response)
+        .setStatus(anyInt());
+
+    new IndexServlet().doPost(request, response);
+    writer.flush();
+
+    assertThat(status.get()).isEqualTo(500);
+    assertThat(body.toString()).contains("Unable to successfully cast vote");
+    assertThat(body.toString()).doesNotContain("Vote successfully cast");
+  }
+}
diff --git a/cloud-sql/postgres/servlet/src/main/java/com/example/cloudsql/IndexServlet.java b/cloud-sql/postgres/servlet/src/main/java/com/example/cloudsql/IndexServlet.java
index 10e73fd094c..50218c92236 100644
--- a/cloud-sql/postgres/servlet/src/main/java/com/example/cloudsql/IndexServlet.java
+++ b/cloud-sql/postgres/servlet/src/main/java/com/example/cloudsql/IndexServlet.java
@@ -123,6 +123,8 @@ public void doPost(HttpServletRequest req, HttpServletResponse resp) throws IOEx
           .write(
               "Unable to successfully cast vote! Please check the application "
                   + "logs for more details.");
+      // Without this return the success response below overwrites the 500 and the error text.
+      return;
       // [END_EXCLUDE]
     }
     // [END cloud_sql_postgres_servlet_connection]
diff --git a/cloud-sql/postgres/servlet/src/test/java/com/example/cloudsql/TestIndexServletPostgresErrorResponse.java b/cloud-sql/postgres/servlet/src/test/java/com/example/cloudsql/TestIndexServletPostgresErrorResponse.java
new file mode 100644
index 00000000000..a255abc20e3
--- /dev/null
+++ b/cloud-sql/postgres/servlet/src/test/java/com/example/cloudsql/TestIndexServletPostgresErrorResponse.java
@@ -0,0 +1,70 @@
+/*
+ * Copyright 2024 Google LLC
+ *
+ * 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 com.example.cloudsql;
+
+import static com.google.common.truth.Truth.assertThat;
+import static org.mockito.ArgumentMatchers.anyInt;
+import static org.mockito.Mockito.doAnswer;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+import java.io.PrintWriter;
+import java.io.StringWriter;
+import java.sql.SQLException;
+import java.util.concurrent.atomic.AtomicInteger;
+import javax.servlet.ServletContext;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import javax.sql.DataSource;
+import org.junit.Test;
+
+/** Covers the doPost error path, which does not need a database. */
+public class TestIndexServletPostgresErrorResponse {
+
+  @Test
+  public void testFailedVoteIsNotReportedAsSuccess() throws Exception {
+    DataSource pool = mock(DataSource.class);
+    when(pool.getConnection()).thenThrow(new SQLException("connection refused"));
+
+    ServletContext context = mock(ServletContext.class);
+    when(context.getAttribute("my-pool")).thenReturn(pool);
+
+    HttpServletRequest request = mock(HttpServletRequest.class);
+    when(request.getServletContext()).thenReturn(context);
+    when(request.getParameter("team")).thenReturn("TABS");
+
+    StringWriter body = new StringWriter();
+    PrintWriter writer = new PrintWriter(body);
+    AtomicInteger status = new AtomicInteger();
+    HttpServletResponse response = mock(HttpServletResponse.class);
+    when(response.getWriter()).thenReturn(writer);
+    doAnswer(
+            invocation -> {
+              status.set(invocation.getArgument(0));
+              return null;
+            })
+        .when(response)
+        .setStatus(anyInt());
+
+    new IndexServlet().doPost(request, response);
+    writer.flush();
+
+    assertThat(status.get()).isEqualTo(500);
+    assertThat(body.toString()).contains("Unable to successfully cast vote");
+    assertThat(body.toString()).doesNotContain("Vote successfully cast");
+  }
+}
diff --git a/cloud-sql/sqlserver/servlet/src/main/java/com/example/cloudsql/IndexServlet.java b/cloud-sql/sqlserver/servlet/src/main/java/com/example/cloudsql/IndexServlet.java
index 60aa1ba8621..890ab5254ac 100644
--- a/cloud-sql/sqlserver/servlet/src/main/java/com/example/cloudsql/IndexServlet.java
+++ b/cloud-sql/sqlserver/servlet/src/main/java/com/example/cloudsql/IndexServlet.java
@@ -97,6 +97,8 @@ public void doPost(HttpServletRequest req, HttpServletResponse resp)
       resp.setStatus(500);
       resp.getWriter().write("Unable to successfully cast vote! Please check the application "
           + "logs for more details.");
+      // Without this return the success response below overwrites the 500 and the error text.
+      return;
       // [END_EXCLUDE]
     }
     // [END cloud_sql_sqlserver_servlet_connection]
diff --git a/cloud-sql/sqlserver/servlet/src/test/java/com/example/cloudsql/TestIndexServletSqlServerErrorResponse.java b/cloud-sql/sqlserver/servlet/src/test/java/com/example/cloudsql/TestIndexServletSqlServerErrorResponse.java
new file mode 100644
index 00000000000..dddff5908b1
--- /dev/null
+++ b/cloud-sql/sqlserver/servlet/src/test/java/com/example/cloudsql/TestIndexServletSqlServerErrorResponse.java
@@ -0,0 +1,70 @@
+/*
+ * Copyright 2024 Google LLC
+ *
+ * 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 com.example.cloudsql;
+
+import static com.google.common.truth.Truth.assertThat;
+import static org.mockito.ArgumentMatchers.anyInt;
+import static org.mockito.Mockito.doAnswer;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+import java.io.PrintWriter;
+import java.io.StringWriter;
+import java.sql.SQLException;
+import java.util.concurrent.atomic.AtomicInteger;
+import javax.servlet.ServletContext;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import javax.sql.DataSource;
+import org.junit.Test;
+
+/** Covers the doPost error path, which does not need a database. */
+public class TestIndexServletSqlServerErrorResponse {
+
+  @Test
+  public void testFailedVoteIsNotReportedAsSuccess() throws Exception {
+    DataSource pool = mock(DataSource.class);
+    when(pool.getConnection()).thenThrow(new SQLException("connection refused"));
+
+    ServletContext context = mock(ServletContext.class);
+    when(context.getAttribute("my-pool")).thenReturn(pool);
+
+    HttpServletRequest request = mock(HttpServletRequest.class);
+    when(request.getServletContext()).thenReturn(context);
+    when(request.getParameter("team")).thenReturn("TABS");
+
+    StringWriter body = new StringWriter();
+    PrintWriter writer = new PrintWriter(body);
+    AtomicInteger status = new AtomicInteger();
+    HttpServletResponse response = mock(HttpServletResponse.class);
+    when(response.getWriter()).thenReturn(writer);
+    doAnswer(
+            invocation -> {
+              status.set(invocation.getArgument(0));
+              return null;
+            })
+        .when(response)
+        .setStatus(anyInt());
+
+    new IndexServlet().doPost(request, response);
+    writer.flush();
+
+    assertThat(status.get()).isEqualTo(500);
+    assertThat(body.toString()).contains("Unable to successfully cast vote");
+    assertThat(body.toString()).doesNotContain("Vote successfully cast");
+  }
+}