set(INSTALL_LIB_DIR "${CMAKE_INSTALL_PREFIX}/lib" CACHE PATH "Installation directory for libraries")
set(INSTALL_INC_DIR "${CMAKE_INSTALL_PREFIX}/include" CACHE PATH "Installation directory for headers")
set(INSTALL_MAN_DIR "${CMAKE_INSTALL_PREFIX}/share/man" CACHE PATH "Installation directory for manual pages")
-set(INSTALL_PKGCONFIG_DIR "${CMAKE_INSTALL_PREFIX}/share/pkgconfig" CACHE PATH "Installation directory for pkgconfig (.pc) files")
+set(INSTALL_PKGCONFIG_DIR "${INSTALL_LIB_DIR}/pkgconfig" CACHE PATH "Installation directory for pkgconfig (.pc) files")
include(CheckTypeSize)
include(CheckSymbolExists)