diff --git a/ares/m4/reentrant.m4 b/ares/m4/reentrant.m4
index b7e9a3453..29cc809ea 100644
--- a/ares/m4/reentrant.m4
+++ b/ares/m4/reentrant.m4
@@ -351,7 +351,7 @@ dnl and that in turn setup.h will define _REENTRANT.
 dnl Internal macro for CARES_CONFIGURE_REENTRANT.
 
 AC_DEFUN([CARES_CONFIGURE_FROM_NOW_ON_WITH_REENTRANT], [
-AC_DEFINE(NEED_REENTRANT, 1,
+AC_DEFINE([NEED_REENTRANT], [1],
   [Define to 1 if _REENTRANT preprocessor symbol must be defined.])
 cat >>confdefs.h <<_ACEOF
 #ifndef _REENTRANT
diff --git a/m4/reentrant.m4 b/m4/reentrant.m4
index 1e448be41..23a1cb77e 100644
--- a/m4/reentrant.m4
+++ b/m4/reentrant.m4
@@ -373,7 +373,7 @@ dnl and that in turn setup.h will define _REENTRANT.
 dnl Internal macro for CURL_CONFIGURE_REENTRANT.
 
 AC_DEFUN([CURL_CONFIGURE_FROM_NOW_ON_WITH_REENTRANT], [
-AC_DEFINE(NEED_REENTRANT, 1,
+AC_DEFINE([NEED_REENTRANT], [1],
   [Define to 1 if _REENTRANT preprocessor symbol must be defined.])
 cat >>confdefs.h <<_ACEOF
 #ifndef _REENTRANT