diff --git a/ares/configure.ac b/ares/configure.ac
index 203f8093ac..4315f5c2e3 100644
--- a/ares/configure.ac
+++ b/ares/configure.ac
@@ -15,7 +15,6 @@ AC_DEFINE_UNQUOTED(OS, "${host}", [cpu-machine-OS])
 
 AC_AIX
 AC_PROG_CC
-AC_PROG_CC_STDC
 AM_PROG_CC_C_O
 AC_PROG_INSTALL