diff --git a/m4/ipopt.m4 b/m4/ipopt.m4 index fb54366f7ab49826e4a108a698f43e5435c4c6f2..1df26d222a6770878d8e04cdc8cab9dbe2ccce45 100644 --- a/m4/ipopt.m4 +++ b/m4/ipopt.m4 @@ -15,7 +15,7 @@ ac_save_PKG_CONFIG_PATH="$PKG_CONFIG_PATH" ## do nothing if --without-ipopt is used AS_IF([test x$with_ipopt != xno], [ # is --with-ipopt=bla used? - AS_IF([test "x$with_ipopt" != x], [ + AS_IF([test "x$with_ipopt" != xyes], [ AS_IF([! test -d $with_ipopt], [ AC_MSG_WARN([IPOpt directory $with_ipopt does not exist]) ], [