diff --git a/m4/boinc_wxwidgets.m4 b/m4/boinc_wxwidgets.m4
index 6c1ed5b257..232885c385 100644
--- a/m4/boinc_wxwidgets.m4
+++ b/m4/boinc_wxwidgets.m4
@@ -9,7 +9,9 @@ AC_DEFUN([BOINC_OPTIONS_WXWIDGETS],[
      [])
 
    AM_OPTIONS_WXCONFIG
-     AM_PATH_WXCONFIG($1, [_ac_cv_have_wxwidgets=yes], [_ac_cv_have_wxwidgets=no])
+     AM_PATH_WXCONFIG([$1],
+       [_ac_cv_have_wxwidgets=yes],
+       [AC_MSG_ERROR([No suitable wxWidgets library found.])])
    AC_CACHE_CHECK([if wxWidgets works],[ac_cv_have_wxwidgets],
     [ac_cv_have_wxwidgets="${_ac_cv_have_wxwidgets}"])
    AC_CACHE_SAVE