diff --git a/doc/CMakeLists.txt b/doc/CMakeLists.txt
--- a/doc/CMakeLists.txt
+++ b/doc/CMakeLists.txt
@@ -1,11 +1,11 @@
 SET(PACKAGE_NAME ${PROJECT_NAME})
 SET(PACKAGE_VERSION ${PROJECT_VERSION})
-SET(abs_top_srcdir ${CMAKE_SOURCE_DIR})
-SET(abs_top_builddir ${CMAKE_BINARY_DIR})
+SET(abs_top_srcdir ${PROJECT_SOURCE_DIR})
+SET(abs_top_builddir ${PROJECT_BINARY_DIR})
 
 CONFIGURE_FILE(
-  ${CMAKE_SOURCE_DIR}/doc/Doxyfile.in
-  ${CMAKE_BINARY_DIR}/doc/Doxyfile
+  ${PROJECT_SOURCE_DIR}/doc/Doxyfile.in
+  ${PROJECT_BINARY_DIR}/doc/Doxyfile
   @ONLY)
 
 IF(DOXYGEN_EXECUTABLE AND GHOSTSCRIPT_EXECUTABLE)