diff --git a/extensions/arc/deployment/src/test/java/io/quarkus/arc/test/decorator/DecoratorOfExternalBeanTest.java b/extensions/arc/deployment/src/test/java/io/quarkus/arc/test/decorator/DecoratorOfExternalBeanTest.java
new file mode 100644
index 0000000000000..8a166fb63c248
--- /dev/null
+++ b/extensions/arc/deployment/src/test/java/io/quarkus/arc/test/decorator/DecoratorOfExternalBeanTest.java
@@ -0,0 +1,49 @@
+package io.quarkus.arc.test.decorator;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.util.List;
+
+import jakarta.decorator.Decorator;
+import jakarta.decorator.Delegate;
+import jakarta.inject.Inject;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.RegisterExtension;
+
+import io.quarkus.arc.test.supplement.SomeBeanInExternalLibrary;
+import io.quarkus.arc.test.supplement.SomeInterfaceInExternalLibrary;
+import io.quarkus.builder.Version;
+import io.quarkus.maven.dependency.Dependency;
+import io.quarkus.test.QuarkusUnitTest;
+
+public class DecoratorOfExternalBeanTest {
+    // the test includes an _application_ decorator (in the Runtime CL) that applies
+    // to a bean that is _outside_ of the application (in the Base Runtime CL)
+
+    @RegisterExtension
+    static final QuarkusUnitTest config = new QuarkusUnitTest()
+            .withApplicationRoot(jar -> jar.addClass(MyDecorator.class))
+            // we need a non-application archive, so cannot use `withAdditionalDependency()`
+            .setForcedDependencies(List.of(Dependency.of("io.quarkus", "quarkus-arc-test-supplement", Version.getVersion())));
+
+    @Inject
+    SomeBeanInExternalLibrary bean;
+
+    @Test
+    public void test() {
+        assertEquals("Delegated: Hello", bean.hello());
+    }
+
+    @Decorator
+    public static class MyDecorator implements SomeInterfaceInExternalLibrary {
+        @Inject
+        @Delegate
+        SomeInterfaceInExternalLibrary delegate;
+
+        @Override
+        public String hello() {
+            return "Delegated: " + delegate.hello();
+        }
+    }
+}
diff --git a/extensions/arc/test-supplement/pom.xml b/extensions/arc/test-supplement/pom.xml
index 0f40b77893883..4f9e04eb3b135 100644
--- a/extensions/arc/test-supplement/pom.xml
+++ b/extensions/arc/test-supplement/pom.xml
@@ -13,4 +13,11 @@
     <name>Quarkus - ArC - Test Supplement</name>
     <description>Supplement archive for ArC tests</description>
 
+    <dependencies>
+        <dependency>
+            <groupId>jakarta.enterprise</groupId>
+            <artifactId>jakarta.enterprise.cdi-api</artifactId>
+        </dependency>
+    </dependencies>
+
 </project>
diff --git a/extensions/arc/test-supplement/src/main/java/io/quarkus/arc/test/supplement/SomeBeanInExternalLibrary.java b/extensions/arc/test-supplement/src/main/java/io/quarkus/arc/test/supplement/SomeBeanInExternalLibrary.java
new file mode 100644
index 0000000000000..1e722755fa73c
--- /dev/null
+++ b/extensions/arc/test-supplement/src/main/java/io/quarkus/arc/test/supplement/SomeBeanInExternalLibrary.java
@@ -0,0 +1,11 @@
+package io.quarkus.arc.test.supplement;
+
+import jakarta.enterprise.context.Dependent;
+
+@Dependent
+public class SomeBeanInExternalLibrary implements SomeInterfaceInExternalLibrary {
+    @Override
+    public String hello() {
+        return "Hello";
+    }
+}
diff --git a/extensions/arc/test-supplement/src/main/java/io/quarkus/arc/test/supplement/SomeInterfaceInExternalLibrary.java b/extensions/arc/test-supplement/src/main/java/io/quarkus/arc/test/supplement/SomeInterfaceInExternalLibrary.java
new file mode 100644
index 0000000000000..f621a3c9d27a0
--- /dev/null
+++ b/extensions/arc/test-supplement/src/main/java/io/quarkus/arc/test/supplement/SomeInterfaceInExternalLibrary.java
@@ -0,0 +1,5 @@
+package io.quarkus.arc.test.supplement;
+
+public interface SomeInterfaceInExternalLibrary {
+    String hello();
+}
diff --git a/extensions/arc/test-supplement/src/main/resources/META-INF/beans.xml b/extensions/arc/test-supplement/src/main/resources/META-INF/beans.xml
new file mode 100644
index 0000000000000..e69de29bb2d1d
diff --git a/independent-projects/arc/processor/src/main/java/io/quarkus/arc/processor/BeanGenerator.java b/independent-projects/arc/processor/src/main/java/io/quarkus/arc/processor/BeanGenerator.java
index da197f726362b..7b763b4f47fb3 100644
--- a/independent-projects/arc/processor/src/main/java/io/quarkus/arc/processor/BeanGenerator.java
+++ b/independent-projects/arc/processor/src/main/java/io/quarkus/arc/processor/BeanGenerator.java
@@ -344,7 +344,9 @@ Collection<Resource> generateClassBean(BeanInfo bean, ClassInfo beanClass) {
             return Collections.emptyList();
         }
 
-        boolean isApplicationClass = applicationClassPredicate.test(beanClass.name()) || bean.isForceApplicationClass();
+        boolean isApplicationClass = applicationClassPredicate.test(beanClass.name())
+                || bean.isForceApplicationClass()
+                || bean.hasBoundDecoratorWhichIsApplicationClass(applicationClassPredicate);
         ResourceClassOutput classOutput = new ResourceClassOutput(isApplicationClass,
                 name -> name.equals(generatedName) ? SpecialType.BEAN : null, generateSources);
 
diff --git a/independent-projects/arc/processor/src/main/java/io/quarkus/arc/processor/BeanInfo.java b/independent-projects/arc/processor/src/main/java/io/quarkus/arc/processor/BeanInfo.java
index 8b3d1ceca018d..89e964f9cab17 100644
--- a/independent-projects/arc/processor/src/main/java/io/quarkus/arc/processor/BeanInfo.java
+++ b/independent-projects/arc/processor/src/main/java/io/quarkus/arc/processor/BeanInfo.java
@@ -18,6 +18,7 @@
 import java.util.OptionalInt;
 import java.util.Set;
 import java.util.function.Consumer;
+import java.util.function.Predicate;
 import java.util.stream.Collectors;
 
 import jakarta.enterprise.inject.Typed;
@@ -514,6 +515,15 @@ public List<DecoratorInfo> getBoundDecorators() {
         return bound;
     }
 
+    boolean hasBoundDecoratorWhichIsApplicationClass(Predicate<DotName> isApplicationClass) {
+        for (DecoratorInfo decorator : getBoundDecorators()) {
+            if (isApplicationClass.test(decorator.getImplClazz().name())) {
+                return true;
+            }
+        }
+        return false;
+    }
+
     /**
      *
      * @return the list of around invoke interceptor methods declared in the hierarchy of a bean class
diff --git a/independent-projects/arc/processor/src/main/java/io/quarkus/arc/processor/ClientProxyGenerator.java b/independent-projects/arc/processor/src/main/java/io/quarkus/arc/processor/ClientProxyGenerator.java
index b7c262df9af8b..f5c64a88e4691 100644
--- a/independent-projects/arc/processor/src/main/java/io/quarkus/arc/processor/ClientProxyGenerator.java
+++ b/independent-projects/arc/processor/src/main/java/io/quarkus/arc/processor/ClientProxyGenerator.java
@@ -98,8 +98,9 @@ Collection<Resource> generate(BeanInfo bean, String beanClassName,
             return Collections.emptyList();
         }
 
-        boolean applicationClass = applicationClassPredicate.test(getApplicationClassTestName(bean));
-        ResourceClassOutput classOutput = new ResourceClassOutput(applicationClass,
+        boolean isApplicationClass = applicationClassPredicate.test(getApplicationClassTestName(bean))
+                || bean.hasBoundDecoratorWhichIsApplicationClass(applicationClassPredicate);
+        ResourceClassOutput classOutput = new ResourceClassOutput(isApplicationClass,
                 name -> name.equals(generatedName) ? SpecialType.CLIENT_PROXY : null, generateSources);
 
         // Foo_ClientProxy extends Foo implements ClientProxy
diff --git a/independent-projects/arc/processor/src/main/java/io/quarkus/arc/processor/SubclassGenerator.java b/independent-projects/arc/processor/src/main/java/io/quarkus/arc/processor/SubclassGenerator.java
index b14ee140c82b4..23ad18173f797 100644
--- a/independent-projects/arc/processor/src/main/java/io/quarkus/arc/processor/SubclassGenerator.java
+++ b/independent-projects/arc/processor/src/main/java/io/quarkus/arc/processor/SubclassGenerator.java
@@ -112,7 +112,9 @@ Collection<Resource> generate(BeanInfo bean, String beanClassName) {
             return Collections.emptyList();
         }
 
-        ResourceClassOutput classOutput = new ResourceClassOutput(applicationClassPredicate.test(bean.getBeanClass()),
+        boolean isApplicationClass = applicationClassPredicate.test(bean.getBeanClass())
+                || bean.hasBoundDecoratorWhichIsApplicationClass(applicationClassPredicate);
+        ResourceClassOutput classOutput = new ResourceClassOutput(isApplicationClass,
                 name -> name.equals(generatedName) ? SpecialType.SUBCLASS : null,
                 generateSources);