diff --git a/resources/CMakeLists.txt b/resources/CMakeLists.txt
index 4e40051..10d7295 100644
--- a/resources/CMakeLists.txt
+++ b/resources/CMakeLists.txt
@@ -14,17 +14,18 @@ function(embed_headers output)
   foreach(header ${HEADERS})
     set_property(DIRECTORY APPEND PROPERTY CMAKE_CONFIGURE_DEPENDS ${header})
 
-    file(REAL_PATH ${header} file_real_path)
-    set(include_path ${CMAKE_CURRENT_SOURCE_DIR}/../include)
+    file(REAL_PATH ${header} header_path)
+    file(REAL_PATH ${CMAKE_SOURCE_DIR}/include include_path)
+    file(REAL_PATH ${CMAKE_SOURCE_DIR} base_path)
 
-    cmake_path(IS_PREFIX include_path ${file_real_path} NORMALIZE in_include)
+    cmake_path(IS_PREFIX include_path ${header_path} NORMALIZE in_include)
     if (${in_include})
-      file(RELATIVE_PATH file_rel_path ${include_path} ${file_real_path})
+      file(RELATIVE_PATH header_rel_path ${include_path} ${header_path})
     else()
-      file(RELATIVE_PATH file_rel_path ${CMAKE_CURRENT_SOURCE_DIR}/.. ${file_real_path})
+      file(RELATIVE_PATH header_rel_path ${base_path} ${header_path})
     endif()
 
-    string(MAKE_C_IDENTIFIER ${file_rel_path} varname)
+    string(MAKE_C_IDENTIFIER ${header_rel_path} varname)
     get_filename_component(filename ${header} NAME)
 
     file(READ ${header} contents)