diff --git a/src/main/java/rife/bld/extension/kotlin/CompileOptions.java b/src/main/java/rife/bld/extension/kotlin/CompileOptions.java
index 002a2e5..a108bdf 100644
--- a/src/main/java/rife/bld/extension/kotlin/CompileOptions.java
+++ b/src/main/java/rife/bld/extension/kotlin/CompileOptions.java
@@ -60,6 +60,7 @@ public class CompileOptions {
     private boolean progressive_;
     private boolean verbose_;
     private boolean wError_;
+    private boolean wExtra_;
 
     /**
      * Specify advanced compiler options.
@@ -374,11 +375,16 @@ public class CompileOptions {
             args.add("-verbose");
         }
 
-        // Werror
+        // Wwrror
         if (wError_) {
             args.add("-Werror");
         }
 
+        // Wextra
+        if (wExtra_) {
+            args.add("-Wextra");
+        }
+
         // advanced option (X)
         if (!advancedOptions_.isEmpty()) {
             advancedOptions_.forEach(it -> args.add("-X" + it));
@@ -597,6 +603,15 @@ public class CompileOptions {
         return wError_;
     }
 
+    /**
+     * Indicates whether additional declaration, expression, and type compiler checks emit warnings.
+     *
+     * @return {@code true} or {@code false}
+     */
+    public boolean isWExtra() {
+        return wExtra_;
+    }
+
     /**
      * Generate metadata for Java 1.8 reflection on method parameters.
      *
@@ -1071,4 +1086,15 @@ public class CompileOptions {
         wError_ = wError;
         return this;
     }
+
+    /**
+     * Enable additional declaration, expression, and type compiler checks that emit warnings if {@code true}.
+     *
+     * @param wExtra {@code true} or {@code false}
+     * @return this operation instance
+     */
+    public CompileOptions wExtra(boolean wExtra) {
+        wExtra_ = wExtra;
+        return this;
+    }
 }
diff --git a/src/test/java/rife/bld/extension/kotlin/CompileOptionsTest.java b/src/test/java/rife/bld/extension/kotlin/CompileOptionsTest.java
index 129ab44..3bc9e25 100644
--- a/src/test/java/rife/bld/extension/kotlin/CompileOptionsTest.java
+++ b/src/test/java/rife/bld/extension/kotlin/CompileOptionsTest.java
@@ -71,7 +71,8 @@ class CompileOptionsTest {
                 .progressive(true)
                 .scriptTemplates("name", "name2")
                 .verbose(true)
-                .wError(true);
+                .wError(true)
+                .wExtra(true);
 
         var matches = List.of(
                 "-api-version", "11",
@@ -97,7 +98,8 @@ class CompileOptionsTest {
                 "-progressive",
                 "-script-templates", "name,name2",
                 "-verbose",
-                "-Werror");
+                "-Werror",
+                "-Wextra");
 
         var args = new ArrayList<List<String>>();
         args.add(options.args());
@@ -234,7 +236,8 @@ class CompileOptionsTest {
                 .progressive(true)
                 .scriptTemplates("template")
                 .verbose(true)
-                .wError(true);
+                .wError(true)
+                .wExtra(true);
 
         try (var softly = new AutoCloseableSoftAssertions()) {
             for (var p : args) {
@@ -340,7 +343,8 @@ class CompileOptionsTest {
                 .progressive(true)
                 .scriptTemplates("name", "name2")
                 .verbose(true)
-                .wError(true);
+                .wError(true)
+                .wExtra(true);
 
         try (var softly = new AutoCloseableSoftAssertions()) {
             softly.assertThat(options.advancedOptions()).containsExactly("xopt1", "xopt2");
@@ -368,6 +372,7 @@ class CompileOptionsTest {
             softly.assertThat(options.plugin()).containsExactly("id:name:value");
             softly.assertThat(options.scriptTemplates()).containsExactly("name", "name2");
             softly.assertThat(options.isWError()).isTrue();
+            softly.assertThat(options.isWExtra()).isTrue();
         }
     }
 }
diff --git a/src/test/resources/kotlinc-args.txt b/src/test/resources/kotlinc-args.txt
index b3c7f27..e764231 100644
--- a/src/test/resources/kotlinc-args.txt
+++ b/src/test/resources/kotlinc-args.txt
@@ -22,4 +22,5 @@
 -script-templates
 -verbose
 -Werror
+-Wextra
 -X