diff --git a/Reconstruction/LwtnnUtils/CMakeLists.txt b/Reconstruction/LwtnnUtils/CMakeLists.txt
index bbce79e3c3b74ca80486ff2d654967d33e12e2d8..a10e47c1630b2f0d1d22cde527f3896610ed0d0d 100644
--- a/Reconstruction/LwtnnUtils/CMakeLists.txt
+++ b/Reconstruction/LwtnnUtils/CMakeLists.txt
@@ -6,12 +6,14 @@ atlas_subdir( LwtnnUtils )
 
 # External dependencies:
 find_package( lwtnn )
+find_package( Eigen )
 
 # Build a shared library:
 atlas_add_library( LwtnnUtils
+  LwtnnUtils/*.h                # <-- for Xcode, not needed otherwise
   src/FastGraph.cxx
   src/FastInputPreprocessor.cxx
   PUBLIC_HEADERS LwtnnUtils
-  INCLUDE_DIRS ${LWTNN_INCLUDE_DIRS}
-  LINK_LIBRARIES ${LWTNN_LIBRARIES} )
+  INCLUDE_DIRS ${LWTNN_INCLUDE_DIRS} ${EIGEN_INCLUDE_DIRS}
+  LINK_LIBRARIES ${LWTNN_LIBRARIES} ${EIGEN_LIBRARIES} )
 
diff --git a/Reconstruction/LwtnnUtils/LwtnnUtils/FastGraph.h b/Reconstruction/LwtnnUtils/LwtnnUtils/FastGraph.h
index 4e257f8d9d66dfbfbcbee9c98b31f9490f94201e..89e26d44d7fe31a2bda6c99504904ce35944874d 100644
--- a/Reconstruction/LwtnnUtils/LwtnnUtils/FastGraph.h
+++ b/Reconstruction/LwtnnUtils/LwtnnUtils/FastGraph.h
@@ -8,8 +8,8 @@
 //
 // [1]: https::www.github.com/lwtnn/lwtnn
 
-#ifndef FAST_GRAPH_H
-#define FAST_GRAPH_H
+#ifndef LWTNN_UTILS_FAST_GRAPH_H
+#define LWTNN_UTILS_FAST_GRAPH_H
 
 #include "lwtnn/lightweight_network_config.hh"
 
diff --git a/Reconstruction/LwtnnUtils/LwtnnUtils/FastInputPreprocessor.h b/Reconstruction/LwtnnUtils/LwtnnUtils/FastInputPreprocessor.h
index 1f9aa4ba39e446a5dc94e2a2891a5201bd31167a..b04688760d61a3276a67762fbbdc7e96e8494007 100644
--- a/Reconstruction/LwtnnUtils/LwtnnUtils/FastInputPreprocessor.h
+++ b/Reconstruction/LwtnnUtils/LwtnnUtils/FastInputPreprocessor.h
@@ -9,8 +9,8 @@
 // [1]: https::www.github.com/lwtnn/lwtnn
 
 
-#ifndef FAST_INPUT_PREPROCESSOR_HH
-#define FAST_INPUT_PREPROCESSOR_HH
+#ifndef LWTNN_UTILS_FAST_INPUT_PREPROCESSOR_H
+#define LWTNN_UTILS_FAST_INPUT_PREPROCESSOR_H
 
 #include "lwtnn/lightweight_network_config.hh"
 #include "lwtnn/Exceptions.hh"
diff --git a/Reconstruction/LwtnnUtils/LwtnnUtils/InputOrder.h b/Reconstruction/LwtnnUtils/LwtnnUtils/InputOrder.h
index 56f8ed097f5dbfe4027eaa41ed4371b2a5bbc117..9df4677d991c4bad004aa173bb57c01c357acf40 100644
--- a/Reconstruction/LwtnnUtils/LwtnnUtils/InputOrder.h
+++ b/Reconstruction/LwtnnUtils/LwtnnUtils/InputOrder.h
@@ -8,8 +8,8 @@
 //
 // [1]: https::www.github.com/lwtnn/lwtnn
 
-#ifndef INPUT_ORDER_H
-#define INPUT_ORDER_H
+#ifndef LWTNN_UTILS_INPUT_ORDER_H
+#define LWTNN_UTILS_INPUT_ORDER_H
 
 #include <vector>
 #include <string>
@@ -33,4 +33,4 @@ namespace lwt::atlas {
 }
 
 
-#endif // INPUT_ORDER_HH
+#endif