diff --git a/sesman/session.c b/sesman/session.c
index 79128e5e..64079a8f 100644
--- a/sesman/session.c
+++ b/sesman/session.c
@@ -89,7 +89,9 @@ session_get_bydata(char *name, int width, int height, int bpp, int type, char *c
     {
         case SCP_SESSION_TYPE_XVNC: /* 0 */
             type = SESMAN_SESSION_TYPE_XVNC; /* 2 */
-            policy |= SESMAN_CFG_SESS_POLICY_D;  /* Xvnc cannot resize */
+            /* Xvnc cannot resize */
+            policy = (enum SESMAN_CFG_SESS_POLICY)
+                     (policy | SESMAN_CFG_SESS_POLICY_D);
             break;
         case SCP_SESSION_TYPE_XRDP: /* 1 */
             type = SESMAN_SESSION_TYPE_XRDP; /* 1 */