diff --git a/core/processor/src/main/java/io/quarkus/annotation/processor/generate_doc/ConfigDocItemFinder.java b/core/processor/src/main/java/io/quarkus/annotation/processor/generate_doc/ConfigDocItemFinder.java
index 26035efd27f36..0e5c0643f18ea 100644
--- a/core/processor/src/main/java/io/quarkus/annotation/processor/generate_doc/ConfigDocItemFinder.java
+++ b/core/processor/src/main/java/io/quarkus/annotation/processor/generate_doc/ConfigDocItemFinder.java
@@ -159,8 +159,6 @@ private List<ConfigDocItem> recursivelyFindConfigItems(Element element, String r
             String name = null;
             String defaultValue = NO_DEFAULT;
             String defaultValueDoc = EMPTY;
-            final TypeMirror typeMirror = unwrapTypeMirror(enclosedElement.asType());
-            String type = typeMirror.toString();
             List<String> acceptedValues = null;
             final TypeElement clazz = (TypeElement) element;
             final String fieldName = enclosedElement.getSimpleName().toString();
@@ -250,6 +248,9 @@ private List<ConfigDocItem> recursivelyFindConfigItems(Element element, String r
                 defaultValue = EMPTY;
             }
 
+            TypeMirror typeMirror = unwrapTypeMirror(enclosedElement.asType());
+            String type = getType(typeMirror);
+
             if (isConfigGroup(type)) {
                 List<ConfigDocItem> groupConfigItems = readConfigGroupItems(configPhase, rootName, name, type,
                         configSection, withinAMap, generateSeparateConfigGroupDocsFiles);
@@ -387,6 +388,15 @@ private TypeMirror unwrapTypeMirror(TypeMirror typeMirror) {
         return typeMirror;
     }
 
+    private String getType(TypeMirror typeMirror) {
+        if (typeMirror instanceof DeclaredType) {
+            DeclaredType declaredType = (DeclaredType) typeMirror;
+            TypeElement typeElement = (TypeElement) declaredType.asElement();
+            return typeElement.getQualifiedName().toString();
+        }
+        return typeMirror.toString();
+    }
+
     private boolean isConfigGroup(String type) {
         if (type.startsWith("java.") || PRIMITIVE_TYPES.contains(type)) {
             return false;