diff --git a/configure.ac b/configure.ac
index 14e0f7f51b8812371b7f7a799f6d31f530347775..5f4639ffa887077536c19cb5aaa9c5b7ecc90c03 100644
--- a/configure.ac
+++ b/configure.ac
@@ -440,6 +440,7 @@ AC_SUBST(TESTDIR)
 AC_SUBST(EXAMPLESDIR)
 AC_SUBST(EXTRAS)
 AC_SUBST(BINDIR)
+AC_SUBST(LIBDIR)
 AC_SUBST(PKGDATADIR)
 AC_SUBST(PKGEXTRABINDIR)
 AC_SUBST(LAUNCHSTYLE)
diff --git a/music-config/predict_rank.py.in b/music-config/predict_rank.py.in
index c2051ebb08309bfa5da28013056ce7d554459cfe..3dbad766cf361d683071c27792f80c4249a34811 100644
--- a/music-config/predict_rank.py.in
+++ b/music-config/predict_rank.py.in
@@ -17,7 +17,7 @@ def c_argc_argv (argv):
 
     return (c_argc, c_argv)
 
-libmusic = ctypes.CDLL ("@libdir@/libmusic-c.so")
+libmusic = ctypes.CDLL ("@LIBDIR@/libmusic-c.so")
 
 def predictRank ():
     return libmusic.MUSIC_predictRank (*c_argc_argv (sys.argv))