diff --git a/CMakeLists.txt b/CMakeLists.txt
index 773e0374..c5fd2995 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -122,9 +122,9 @@ endif()
 
 include(GNUInstallDirs)
 set(prefix "${CMAKE_INSTALL_PREFIX}")
-set(exec_prefix "${CMAKE_INSTALL_FULL_BINDIR}")
-set(libdir "${CMAKE_INSTALL_FULL_LIBDIR}")
-set(includedir "${CMAKE_INSTALL_FULL_INCLUDEDIR}")
+set(exec_prefix "\${prefix}/${CMAKE_INSTALL_BINDIR}")
+set(libdir "\${prefix}/${CMAKE_INSTALL_LIBDIR}")
+set(includedir "\${prefix}/${CMAKE_INSTALL_INCLUDEDIR}")
 set(VERSION "${PROJECT_VERSION_MAJOR}.${PROJECT_VERSION_MINOR}.${PROJECT_VERSION_PATCH}")
 
 configure_file(qrencode.1.in qrencode.1 @ONLY)