--- a/opus.m4
+++ b/opus.m4
@@ -22,7 +22,7 @@ AC_ARG_ENABLE(opustest,AC_HELP_STRING([--disable-opustest],[Do not try to compil
   elif test "x$opus_prefix" != "x" ; then
     OPUS_LIBS="-L$opus_prefix/lib"
   elif test "x$prefix" != "xNONE" ; then
-    OPUS_LIBS="-L$prefix/lib"
+    OPUS_LIBS="-L${libdir}"
   fi
 
   if test "x$opus_prefix" != "xno" ; then