diff --git a/mozilla/directory/c-sdk/configure b/mozilla/directory/c-sdk/configure
index a7c9055d7d8..97a79dcafa6 100755
--- a/mozilla/directory/c-sdk/configure
+++ b/mozilla/directory/c-sdk/configure
@@ -1661,18 +1661,6 @@ if test "${enable_64bit+set}" = set; then
    if test "$enableval" = "yes"; then
 	    USE_64=1 ; export USE_64
       fi
-else
-
-        arch=`uname -m`
-        case $arch in
-             x86_64|ppc64|ia64|s390x) USE_64=1 ; export USE_64 ;;
-             sun4u) instr_set=`optisa \`isalist\``
-                    case $instr_set in
-                         sparcv9*) USE_64=1 ; export USE_64 ;;
-                    esac
-             ;;
-        esac
-
 fi;
 
 # Check whether --enable-mdupdate or --disable-mdupdate was given.
diff --git a/mozilla/directory/c-sdk/configure.in b/mozilla/directory/c-sdk/configure.in
index e5b8a8ec50a..909c4573416 100644
--- a/mozilla/directory/c-sdk/configure.in
+++ b/mozilla/directory/c-sdk/configure.in
@@ -200,18 +200,7 @@ AC_ARG_ENABLE(64bit,
     [ if test "$enableval" = "yes"; then
 	    USE_64=1 ; export USE_64
       fi ],
-    [
-dnl if the user specified nothing, just guess based on machine type
-        arch=`uname -m`
-        case $arch in
-             x86_64|ppc64|ia64|s390x) USE_64=1 ; export USE_64 ;;
-             sun4u) instr_set=`optisa \`isalist\``
-                    case $instr_set in
-                         sparcv9*) USE_64=1 ; export USE_64 ;;
-                    esac
-             ;;
-        esac
-    ])
+    [])
 
 AC_ARG_ENABLE(mdupdate,
     [  --enable-mdupdate       Enable use of certain compilers' mdupdate feature],