diff --git a/src/main/java/org/codehaus/gmavenplus/mojo/AbstractCompileMojo.java b/src/main/java/org/codehaus/gmavenplus/mojo/AbstractCompileMojo.java
index fe1a20bb..edd34d94 100644
--- a/src/main/java/org/codehaus/gmavenplus/mojo/AbstractCompileMojo.java
+++ b/src/main/java/org/codehaus/gmavenplus/mojo/AbstractCompileMojo.java
@@ -44,6 +44,11 @@
  */
 public abstract class AbstractCompileMojo extends AbstractGroovySourcesMojo {
 
+    /**
+     * Groovy 4.0.6 version.
+     */
+    protected static final Version GROOVY_4_0_6 = new Version(4, 0, 6);
+
     /**
      * Groovy 4.0.2 version.
      */
@@ -196,6 +201,7 @@ public abstract class AbstractCompileMojo extends AbstractGroovySourcesMojo {
      * Using 17 requires Groovy >= 3.0.8 or Groovy > 4.0.0-alpha-3.
      * Using 18 requires Groovy > 4.0.0-beta-1.
      * Using 19 requires Groovy > 4.0.2.
+     * Using 20 requires Groovy > 4.0.6.
      */
     @Parameter(property = "maven.compiler.target", defaultValue = "1.8")
     protected String targetBytecode;
@@ -484,7 +490,11 @@ protected Object setupCompilerConfiguration(final File compileOutputDirectory, f
      * org.codehaus.groovy.classgen.asm.WriterController.
      */
     protected void verifyGroovyVersionSupportsTargetBytecode() {
-        if ("19".equals(targetBytecode)) {
+        if ("20".equals(targetBytecode)) {
+            if (groovyOlderThan(GROOVY_4_0_6)) {
+                throw new IllegalArgumentException("Target bytecode " + targetBytecode + " requires Groovy " + GROOVY_4_0_6 + " or newer.");
+            }
+        } else if ("19".equals(targetBytecode)) {
             if (groovyOlderThan(GROOVY_4_0_2)) {
                 throw new IllegalArgumentException("Target bytecode " + targetBytecode + " requires Groovy " + GROOVY_4_0_2 + " or newer.");
             }
diff --git a/src/main/java/org/codehaus/gmavenplus/mojo/AbstractGenerateStubsMojo.java b/src/main/java/org/codehaus/gmavenplus/mojo/AbstractGenerateStubsMojo.java
index dfe91a95..4a66a058 100644
--- a/src/main/java/org/codehaus/gmavenplus/mojo/AbstractGenerateStubsMojo.java
+++ b/src/main/java/org/codehaus/gmavenplus/mojo/AbstractGenerateStubsMojo.java
@@ -46,6 +46,11 @@
  */
 public abstract class AbstractGenerateStubsMojo extends AbstractGroovyStubSourcesMojo {
 
+    /**
+     * Groovy 4.0.6 version.
+     */
+    protected static final Version GROOVY_4_0_6 = new Version(4, 0, 6);
+
     /**
      * Groovy 4.0.2 version.
      */
@@ -199,6 +204,7 @@ public abstract class AbstractGenerateStubsMojo extends AbstractGroovyStubSource
      * Using 17 requires Groovy >= 3.0.8 or Groovy > 4.0.0-alpha-3.
      * Using 18 requires Groovy > 4.0.0-beta-1.
      * Using 19 requires Groovy > 4.0.2.
+     * Using 20 requires Groovy > 4.0.6.
      *
      * @since 1.0-beta-3
      */
@@ -411,7 +417,11 @@ protected void resetStubModifiedDates(final Set<File> stubs) {
      * org.codehaus.groovy.classgen.asm.WriterController.
      */
     protected void verifyGroovyVersionSupportsTargetBytecode() {
-        if ("19".equals(targetBytecode)) {
+        if ("20".equals(targetBytecode)) {
+            if (groovyOlderThan(GROOVY_4_0_6)) {
+                throw new IllegalArgumentException("Target bytecode " + targetBytecode + " requires Groovy " + GROOVY_4_0_6 + " or newer.");
+            }
+        } else if ("19".equals(targetBytecode)) {
             if (groovyOlderThan(GROOVY_4_0_2)) {
                 throw new IllegalArgumentException("Target bytecode " + targetBytecode + " requires Groovy " + GROOVY_4_0_2 + " or newer.");
             }
diff --git a/src/test/java/org/codehaus/gmavenplus/mojo/AbstractCompileMojoTest.java b/src/test/java/org/codehaus/gmavenplus/mojo/AbstractCompileMojoTest.java
index 22493431..8657b1ce 100644
--- a/src/test/java/org/codehaus/gmavenplus/mojo/AbstractCompileMojoTest.java
+++ b/src/test/java/org/codehaus/gmavenplus/mojo/AbstractCompileMojoTest.java
@@ -391,6 +391,20 @@ public void testJava19WithSupportedGroovy() {
         testMojo.verifyGroovyVersionSupportsTargetBytecode();
     }
 
+    @Test(expected = IllegalArgumentException.class)
+    public void testJava20WithUnsupportedGroovy() {
+        testMojo = new TestMojo("4.0.5");
+        testMojo.targetBytecode = "20";
+        testMojo.verifyGroovyVersionSupportsTargetBytecode();
+    }
+
+    @Test
+    public void testJava20WithSupportedGroovy() {
+        testMojo = new TestMojo("4.0.6");
+        testMojo.targetBytecode = "20";
+        testMojo.verifyGroovyVersionSupportsTargetBytecode();
+    }
+
     @Test(expected = IllegalArgumentException.class)
     public void testUnrecognizedJava() {
         testMojo = new TestMojo("2.1.2");
diff --git a/src/test/java/org/codehaus/gmavenplus/mojo/AbstractGenerateStubsMojoTest.java b/src/test/java/org/codehaus/gmavenplus/mojo/AbstractGenerateStubsMojoTest.java
index 88e40732..1ba2d433 100644
--- a/src/test/java/org/codehaus/gmavenplus/mojo/AbstractGenerateStubsMojoTest.java
+++ b/src/test/java/org/codehaus/gmavenplus/mojo/AbstractGenerateStubsMojoTest.java
@@ -418,6 +418,20 @@ public void testJava19WithSupportedGroovy() {
         testMojo.verifyGroovyVersionSupportsTargetBytecode();
     }
 
+    @Test(expected = IllegalArgumentException.class)
+    public void testJava20WithUnsupportedGroovy() {
+        testMojo = new TestMojo("4.0.5");
+        testMojo.targetBytecode = "20";
+        testMojo.verifyGroovyVersionSupportsTargetBytecode();
+    }
+
+    @Test
+    public void testJava20WithSupportedGroovy() {
+        testMojo = new TestMojo("4.0.6");
+        testMojo.targetBytecode = "20";
+        testMojo.verifyGroovyVersionSupportsTargetBytecode();
+    }
+
     @Test(expected = IllegalArgumentException.class)
     public void testUnrecognizedJava() {
         testMojo = new TestMojo("2.1.2");