diff --git a/modules/openapi-generator-maven-plugin/examples/java-client.xml b/modules/openapi-generator-maven-plugin/examples/java-client.xml
index 0161bd026ea..c08e9f54908 100644
--- a/modules/openapi-generator-maven-plugin/examples/java-client.xml
+++ b/modules/openapi-generator-maven-plugin/examples/java-client.xml
@@ -67,6 +67,7 @@
                             <apiPackage>remote.org.openapitools.client.api</apiPackage>
                             <modelPackage>remote.org.openapitools.client.model</modelPackage>
                             <invokerPackage>remote.org.openapitools.client</invokerPackage>
+                            <cleanupOutput>true</cleanupOutput>
                         </configuration>
                     </execution>
                 </executions>
@@ -76,8 +77,8 @@
                 <artifactId>maven-compiler-plugin</artifactId>
                 <version>3.8.1</version>
                 <configuration>
-                    <source>1.7</source>
-                    <target>1.7</target>
+                    <source>1.8</source>
+                    <target>1.8</target>
                     <proc>none</proc>
                 </configuration>
             </plugin>
diff --git a/modules/openapi-generator-maven-plugin/examples/kotlin.xml b/modules/openapi-generator-maven-plugin/examples/kotlin.xml
index 34b94a80f20..e084401a9ec 100644
--- a/modules/openapi-generator-maven-plugin/examples/kotlin.xml
+++ b/modules/openapi-generator-maven-plugin/examples/kotlin.xml
@@ -26,6 +26,7 @@
 						<configuration>
 							<!-- specify the swagger yaml -->
 							<inputSpec>${project.basedir}/swagger.yaml</inputSpec>
+							<cleanupOutput>true</cleanupOutput>
 
 							<!-- target to generate kotlin client code -->
 							<generatorName>kotlin</generatorName>
diff --git a/modules/openapi-generator-maven-plugin/examples/multi-module/java-client/pom.xml b/modules/openapi-generator-maven-plugin/examples/multi-module/java-client/pom.xml
index 112163677f9..646168963fb 100644
--- a/modules/openapi-generator-maven-plugin/examples/multi-module/java-client/pom.xml
+++ b/modules/openapi-generator-maven-plugin/examples/multi-module/java-client/pom.xml
@@ -59,8 +59,8 @@
                 <artifactId>maven-compiler-plugin</artifactId>
                 <version>3.8.1</version>
                 <configuration>
-                    <source>1.7</source>
-                    <target>1.7</target>
+                    <source>1.8</source>
+                    <target>1.8</target>
                     <proc>none</proc>
                 </configuration>
             </plugin>
diff --git a/modules/openapi-generator-maven-plugin/src/main/java/org/openapitools/codegen/plugin/CodeGenMojo.java b/modules/openapi-generator-maven-plugin/src/main/java/org/openapitools/codegen/plugin/CodeGenMojo.java
index 48f2d6ee07d..a7780239b2c 100644
--- a/modules/openapi-generator-maven-plugin/src/main/java/org/openapitools/codegen/plugin/CodeGenMojo.java
+++ b/modules/openapi-generator-maven-plugin/src/main/java/org/openapitools/codegen/plugin/CodeGenMojo.java
@@ -41,6 +41,7 @@ import java.util.Set;
 import com.google.common.io.ByteSource;
 import com.google.common.io.CharSource;
 import io.swagger.v3.parser.util.ClasspathHelper;
+import org.apache.commons.io.FileUtils;
 import org.apache.commons.lang3.StringUtils;
 import org.apache.maven.plugin.AbstractMojo;
 import org.apache.maven.plugin.MojoExecution;
@@ -99,6 +100,9 @@ public class CodeGenMojo extends AbstractMojo {
     @Parameter(name = "output", property = "openapi.generator.maven.plugin.output")
     private File output;
 
+    @Parameter(name = "cleanupOutput", property = "openapi.generator.maven.plugin.cleanupOutput", defaultValue = "false")
+    private boolean cleanupOutput;
+
     /**
      * Location of the OpenAPI spec, as URL or file.
      */
@@ -494,6 +498,16 @@ public class CodeGenMojo extends AbstractMojo {
                     LifecyclePhase.GENERATE_TEST_SOURCES.id().equals(mojo.getLifecyclePhase()) ?
                             "generated-test-sources/openapi" : "generated-sources/openapi");
         }
+
+        if (cleanupOutput) {
+            try {
+                FileUtils.deleteDirectory(output);
+                LOGGER.info("Previous run output is removed from {}", output);
+            } catch (IOException e) {
+                LOGGER.warn("Failed to clean-up output directory {}", output, e);
+            }
+        }
+
         addCompileSourceRootIfConfigured();
 
         try {