diff -Nrup a/cmake/Modules/GeneratePkgConfig/pkg-config.cmake.in b/cmake/Modules/GeneratePkgConfig/pkg-config.cmake.in
--- a/cmake/Modules/GeneratePkgConfig/pkg-config.cmake.in	2021-03-28 23:43:23.000000000 +0200
+++ b/cmake/Modules/GeneratePkgConfig/pkg-config.cmake.in	2021-05-26 11:08:45.078272070 +0200
@@ -1,5 +1,5 @@
 prefix=@CMAKE_INSTALL_PREFIX@
-libdir=${prefix}/@_INSTALL_LIBDIR@
+libdir=@_INSTALL_LIBDIR@
 
 Name: @_PROJECT_NAME@
 Description: @_PROJECT_DESCRIPTION@