diff --git a/aegisub/configure.in b/aegisub/configure.in
index 52ab0405d..52c262e02 100644
--- a/aegisub/configure.in
+++ b/aegisub/configure.in
@@ -185,6 +185,7 @@ CHECK_GNU_MAKE
 AC_PROG_CC
 AC_PROG_CXX
 AC_LANG(C++)
+define([AC_LIBTOOL_LANG_F77_CONFIG], [:])
 AC_PROG_LIBTOOL
 AC_PROG_INSTALL
 PKG_PROG_PKG_CONFIG([pkgconfig_required_version])