--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -535,7 +535,7 @@
   RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
   ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
   LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
-  PUBLIC_HEADER DESTINATION ${CMAKE_INSTALL_INCLUDEDIR})
+  PUBLIC_HEADER DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}${NAMESPACE_INSTALL_INCLUDEDIR})
 
 if(ENABLE_FORTRAN)
   install(TARGETS xc xcf03 xcf90
@@ -543,7 +543,7 @@
     RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
     ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
     LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
-    PUBLIC_HEADER DESTINATION ${CMAKE_INSTALL_INCLUDEDIR})
+    PUBLIC_HEADER DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}${NAMESPACE_INSTALL_INCLUDEDIR})
   install(FILES "${PROJECT_BINARY_DIR}/xc_f03_lib_m.mod"
     DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}${NAMESPACE_INSTALL_INCLUDEDIR})
   install(FILES "${PROJECT_BINARY_DIR}/xc_f90_lib_m.mod"
@@ -559,7 +559,7 @@
 
 target_compile_definitions(xc INTERFACE USING_${PN})
 target_include_directories(xc INTERFACE
-  $<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>)
+  $<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}${NAMESPACE_INSTALL_INCLUDEDIR}>)
 
 # <<<  Export Config  >>>
 
