diff --git a/memcached.c b/memcached.c
index 59b42849fe..c074aa602e 100644
--- a/memcached.c
+++ b/memcached.c
@@ -2493,27 +2493,32 @@ static void process_update_command(conn *c, token_t *tokens, const size_t ntoken
 
     // does cas value exist?
     if (handle_cas) {
-        if (!safe_strtoull(tokens[5].value, &req_cas_id)
-            || vlen < 0 ) {
+        if (!safe_strtoull(tokens[5].value, &req_cas_id)) {
             out_string(c, "CLIENT_ERROR bad command line format");
             return;
         }
     }
 
+    vlen += 2;
+    if (vlen < 0 || vlen - 2 < 0) {
+        out_string(c, "CLIENT_ERROR bad command line format");
+        return;
+    }
+
     if (settings.detail_enabled) {
         stats_prefix_record_set(key, nkey);
     }
 
-    it = item_alloc(key, nkey, flags, realtime(exptime), vlen+2);
+    it = item_alloc(key, nkey, flags, realtime(exptime), vlen);
 
     if (it == 0) {
-        if (! item_size_ok(nkey, flags, vlen + 2))
+        if (! item_size_ok(nkey, flags, vlen))
             out_string(c, "SERVER_ERROR object too large for cache");
         else
             out_string(c, "SERVER_ERROR out of memory storing object");
         /* swallow the data line */
         c->write_and_go = conn_swallow;
-        c->sbytes = vlen + 2;
+        c->sbytes = vlen;
 
         /* Avoid stale data persisting in cache because we failed alloc.
          * Unacceptable for SET. Anywhere else too? */
diff --git a/t/issue_70.t b/t/issue_70.t
new file mode 100644
index 0000000000..95e39db11c
--- /dev/null
+++ b/t/issue_70.t
@@ -0,0 +1,22 @@
+#!/usr/bin/perl
+
+use strict;
+use Test::More tests => 4;
+use FindBin qw($Bin);
+use lib "$Bin/lib";
+use MemcachedTest;
+
+my $server = new_memcached();
+my $sock = $server->sock;
+
+print $sock "set issue70 0 0 0\r\n\r\n";
+is (scalar <$sock>, "STORED\r\n", "stored issue70");
+
+print $sock "set issue70 0 0 -1\r\n";
+is (scalar <$sock>, "CLIENT_ERROR bad command line format\r\n");
+
+print $sock "set issue70 0 0 4294967295\r\n";
+is (scalar <$sock>, "CLIENT_ERROR bad command line format\r\n");
+
+print $sock "set issue70 0 0 2147483647\r\nscoobyscoobydoo";
+is (scalar <$sock>, "CLIENT_ERROR bad command line format\r\n");