diff --git a/CMakeLists.txt b/CMakeLists.txt
index c5abd8f..01e5f44 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -26,7 +26,7 @@ add_library(
 
 target_include_directories(
     ikarus PUBLIC
-    $<BUILD_INTERFACE:${PROJECT_SOURCE_DIR}/include>
+    ${CMAKE_CURRENT_LIST_DIR}/include
 )
 
 target_include_directories(
diff --git a/include/ikarus/persistence/project.h b/include/ikarus/persistence/project.h
index c4406f8..f08107b 100644
--- a/include/ikarus/persistence/project.h
+++ b/include/ikarus/persistence/project.h
@@ -3,6 +3,7 @@
 /// \file project.h
 /// \author Folling <folling@ikarus.world>
 
+#include <ikarus/errors.h>
 #include <ikarus/macros.h>
 #include <ikarus/stdtypes.h>