diff --git a/slang/ChangeLog b/slang/ChangeLog
index baa643254..7c16f0066 100644
--- a/slang/ChangeLog
+++ b/slang/ChangeLog
@@ -1,3 +1,8 @@
+2004-10-27  Nerijus Baliunas  <nerijus@users.sourceforge.net>
+
+	* include/slang.h: Define __unix__ if _AIX is defined.
+	Needed on AIX.
+
 2004-10-14  Andrew V. Samoilov  <sav@bcs.zp.ua>
 
 	* sldisply.c (tt_sprintf): Add missed break.
diff --git a/slang/include/slang.h b/slang/include/slang.h
index af7a1592c..c9a42a6ec 100644
--- a/slang/include/slang.h
+++ b/slang/include/slang.h
@@ -24,7 +24,7 @@
 # endif
 #endif /* __watcomc__ */
 
-#if defined(unix) || defined(__unix)
+#if defined(unix) || defined(__unix) || defined (_AIX)
 # ifndef __unix__
 #  define __unix__ 1
 # endif