diff --git a/platform/unix/automagic b/platform/unix/automagic
index dfa3e4c6b..eca181b0d 100755
--- a/platform/unix/automagic
+++ b/platform/unix/automagic
@@ -18,7 +18,7 @@ AUTOMAKE=$(which automake)
 [[ -x ${AUTOMAKE} ]]   || die "Could not find automake."
 
 automagic() {
-	cp platform/unix/configure.in .
+	cp platform/unix/configure.ac .
 	cp platform/unix/Makefile.am .
 
 	if ! sh platform/unix/gen-makefile; then
diff --git a/platform/unix/configure.in b/platform/unix/configure.ac
similarity index 98%
rename from platform/unix/configure.in
rename to platform/unix/configure.ac
index 2ab096e06..8ba3bc264 100644
--- a/platform/unix/configure.in
+++ b/platform/unix/configure.ac
@@ -6,7 +6,7 @@ AC_CONFIG_SRCDIR([src/love.cpp])
 AM_INIT_AUTOMAKE([foreign -Wall foreign tar-ustar silent-rules])
 AM_SILENT_RULES
 AC_PREFIX_DEFAULT([/usr])
-AM_PROG_AR
+m4_ifdef([AM_PROG_AR], [AM_PROG_AR])
 AC_PROG_LIBTOOL
 AC_PROG_CC
 AC_PROG_CXX