diff --git a/mozilla/build/autoconf/config.guess b/mozilla/build/autoconf/config.guess
index 237caa73139..5d661f1f536 100755
--- a/mozilla/build/autoconf/config.guess
+++ b/mozilla/build/autoconf/config.guess
@@ -1044,6 +1044,13 @@ EOF
     NSR-W:NONSTOP_KERNEL:*:*)
 	echo nsr-tandem-nsk${UNAME_RELEASE}
 	exit 0 ;;
+    *:OS/2:*:*)
+	if test "$VACPP" = "yes"; then
+		echo "i386-pc-os2_vacpp"
+    else
+    	echo "i386-pc-os2_emx"
+	fi
+    exit 0;;
 esac
 
 #echo '(No uname command or uname output not recognized.)' 1>&2
diff --git a/mozilla/build/autoconf/config.sub b/mozilla/build/autoconf/config.sub
index db004455b38..987ac5ca7e8 100755
--- a/mozilla/build/autoconf/config.sub
+++ b/mozilla/build/autoconf/config.sub
@@ -918,6 +918,10 @@ case $os in
 	-gnu/linux*)
 		os=`echo $os | sed -e 's|gnu/linux|linux-gnu|'`
 		;;
+	-os2_emx)
+		;;
+	-os2_vacpp)
+		;;
 	# First accept the basic system types.
 	# The portable systems comes first.
 	# Each alternative MUST END IN A *, to match a version number.