diff --git a/include/caosdb/protobuf_helper.h b/include/caosdb/protobuf_helper.h
index 3cfa3d433d540c545fd3d96789e9cec9166022ee..9a73c0d726b25a792232530d0e01852d9c0b2e99 100644
--- a/include/caosdb/protobuf_helper.h
+++ b/include/caosdb/protobuf_helper.h
@@ -22,9 +22,11 @@
 #ifndef CAOSDB_PROTOBUF_HELPER_H
 #define CAOSDB_PROTOBUF_HELPER_H
 
-#include "caosdb/status_code.h"
-#include <google/protobuf/arena.h>         // for Arena
-#include <google/protobuf/extension_set.h> // for Arena
+#include "caosdb/status_code.h"             // for StatusCode, SUCCESS
+#include <google/protobuf/arena.h>          // for Arena
+#include <google/protobuf/extension_set.h>  // for Arena
+#include <google/protobuf/util/json_util.h> // for JsonOptions, MessageToJs...
+#include <string>                           // for string
 
 #define CAOSDB_DEBUG_MESSAGE_STRING(message, out)                                                  \
   std::string out;                                                                                 \
@@ -47,6 +49,14 @@ public:
     return StatusCode::SUCCESS;
   }
 
+  /**
+   * Return a json representation of this object.
+   */
+  inline auto ToString() const noexcept -> const std::string {
+    CAOSDB_DEBUG_MESSAGE_STRING(*wrapped, out)
+    return out;
+  }
+
 protected:
   ProtoMessageWrapper() : ProtoMessageWrapper(Arena::CreateMessage<P>(get_arena())) {}
   ProtoMessageWrapper(P *wrapped) : wrapped(wrapped) {}
diff --git a/include/caosdb/value.h b/include/caosdb/value.h
index 20bbead6afee5c1e9f2e2a9a86c2705600bf4411..f6de040dcf02fb1600f170f2e18817ed4e2db883 100644
--- a/include/caosdb/value.h
+++ b/include/caosdb/value.h
@@ -22,17 +22,13 @@
 #ifndef CAOSDB_VALUE_H
 #define CAOSDB_VALUE_H
 #include "caosdb/protobuf_helper.h"         // for ProtoMessageWrapper
-#include "caosdb/logging.h"                 // IWYU pragma: keep
 #include "caosdb/entity/v1alpha1/main.pb.h" // for RepeatedPtrField, Message
-
-#include <cstdint>                                  // for int64_t
-#include <google/protobuf/arena.h>                  // for Arena
-#include <google/protobuf/generated_message_util.h> // for Arena
-#include <google/protobuf/util/json_util.h>         // IWYU pragma: keep
-#include <memory>                                   // for unique_ptr
-#include <string>                                   // for string, operator==
-#include <utility>                                  // for move
-#include <vector>                                   // for vector
+#include <cstdint>                          // for int64_t
+#include <google/protobuf/arena.h>          // for Arena
+#include <memory>                           // for unique_ptr
+#include <string>                           // for string, operator==
+#include <utility>                          // for move
+#include <vector>                           // for vector
 
 #define LIST_VALUE_CONSTRUCTOR(TYPE, SETTER)                                                       \
   explicit inline Value(const std::vector<TYPE> &values) : ProtoMessageWrapper<ProtoValue>() {     \
@@ -412,11 +408,6 @@ public:
     return *this;
   }
 
-  inline auto ToString() const noexcept -> const std::string {
-    CAOSDB_DEBUG_MESSAGE_STRING(*wrapped, out)
-    return out;
-  }
-
   friend class Entity;
   friend class Property;
 
diff --git a/src/caosdb/entity.cpp b/src/caosdb/entity.cpp
index 977fb69e63a9741705506b08a9366a41dafcf7ad..8f737602bbda62bbae8e8dcf8f287e95fd82aa09 100644
--- a/src/caosdb/entity.cpp
+++ b/src/caosdb/entity.cpp
@@ -20,13 +20,12 @@
  *
  */
 #include "caosdb/entity.h"
-#include "caosdb/data_type.h"                       // for DataType
-#include "caosdb/entity/v1alpha1/main.pb.h"         // for Messages
-#include "caosdb/protobuf_helper.h"                 // for get_arena
-#include "caosdb/value.h"                           // for Value
-#include <google/protobuf/arena.h>                  // for Arena
-#include <google/protobuf/generated_message_util.h> // for Arena::Create...
-#include <new>                                      // for operator new
+#include "caosdb/data_type.h"               // for DataType
+#include "caosdb/entity/v1alpha1/main.pb.h" // for Messages
+#include "caosdb/protobuf_helper.h"         // for get_arena
+#include "caosdb/value.h"                   // for Value
+#include <google/protobuf/arena.h>          // for Arena
+#include <new>                              // for operator new
 
 namespace caosdb::entity {
 using ProtoParent = caosdb::entity::v1alpha1::Parent;