diff --git a/m4/fsusage.m4 b/m4/fsusage.m4
index 67db3bc0c..8a730bf10 100644
--- a/m4/fsusage.m4
+++ b/m4/fsusage.m4
@@ -1,4 +1,4 @@
-#serial 4
+#serial 5
 
 # From fileutils/configure.in
 
@@ -187,6 +187,6 @@ AC_TRY_CPP([#include <sys/filsys.h>],
   ac_fsusage_space=yes)
 fi
 
-AS_IFELSE([test $ac_fsusage_space = yes], [$1], [$2])dnl
+AS_IF([test $ac_fsusage_space = yes], [$1], [$2])dnl
 
 ])