diff --git a/ChangeLog b/ChangeLog
index 170054f59c8..ae2cc203725 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2002-03-15  Eli Zaretskii  <eliz@is.elta.co.il>
+
+	* configure.in: Support AIX 5.1.
+
 2002-03-10  Jan D.  <Jan.Djarv@mbox200.swipnet.se>
 
 	* configure.in: Added test for X Session Management (HAVE_X_SM).
diff --git a/configure.in b/configure.in
index c1d324fab36..0ea845f0535 100644
--- a/configure.in
+++ b/configure.in
@@ -605,6 +605,9 @@ case "${canonical}" in
   rs6000-ibm-aix4.2* | powerpc-ibm-aix4.2*  )
     machine=ibmrs6000 opsys=aix4-2
   ;;
+  rs6000-ibm-aix5.1* | powerpc-ibm-aix5.1*  )
+    machine=ibmrs6000 opsys=aix4-2
+  ;;
   rs6000-ibm-aix4.0* | powerpc-ibm-aix4.0*  )
     machine=ibmrs6000 opsys=aix4
   ;;