diff --git a/ChangeLog b/ChangeLog
index 718a7fece..614f3d93d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,6 @@
+20001020
+ - (djm) Don't define _REENTRANT for SNI/Reliant Unix
+
 20001018
  - (stevesk) Add initial support for setproctitle().  Current
    support is for the HP-UX pstat(PSTAT_SETCMD, ...) method.
diff --git a/defines.h b/defines.h
index 79d98e2e0..3626bd90d 100644
--- a/defines.h
+++ b/defines.h
@@ -2,7 +2,7 @@
 #define _DEFINES_H
 
 /* Some platforms need this for the _r() functions */
-#ifndef _REENTRANT
+#if !defined(_REENTRANT) && !defined(SNI)
 # define _REENTRANT 1
 #endif