diff --git a/cpukit/ChangeLog b/cpukit/ChangeLog
index 7a1e8be427..43e396d8bb 100644
--- a/cpukit/ChangeLog
+++ b/cpukit/ChangeLog
@@ -1,3 +1,8 @@
+2007-11-27	Joel Sherrill <joel.sherrill@OARcorp.com>
+
+	* libnetworking/netinet/in_cksum.c: ARM optimized version does not
+	support Thumb.
+
 2007-11-26	Joel Sherrill <joel.sherrill@oarcorp.com>
 
 	* telnetd/pty.c, telnetd/telnetd.c, telnetd/telnetd.h: Style clean up.
diff --git a/cpukit/libnetworking/netinet/in_cksum.c b/cpukit/libnetworking/netinet/in_cksum.c
index 833ac44357..dd01e6241d 100644
--- a/cpukit/libnetworking/netinet/in_cksum.c
+++ b/cpukit/libnetworking/netinet/in_cksum.c
@@ -42,8 +42,9 @@
  */
 
 
-#if (defined(__GNUC__) && defined(__arm__))
+#if (defined(__GNUC__) && (defined(__arm__) && !defined(__thumb__))) 
 
+/* This currently does not support Thumb assembly */
 #include "in_cksum_arm.h"
 
 #elif (defined(__GNUC__) && defined(__i386__))