diff --git a/src/modules/kvs/kvs.c b/src/modules/kvs/kvs.c
index 0e6638815804..761478f8361e 100644
--- a/src/modules/kvs/kvs.c
+++ b/src/modules/kvs/kvs.c
@@ -1727,6 +1727,12 @@ static void relayfence_request_cb (flux_t *h, flux_msg_handler_t *mh,
         }
     }
 
+    if (fence_get_flags (f) != flags
+        || fence_get_nprocs (f) != nprocs) {
+        errno = EINVAL;
+        goto error;
+    }
+
     if (fence_add_request_data (f, ops) < 0) {
         flux_log_error (h, "%s: fence_add_request_data", __FUNCTION__);
         goto error;
@@ -1792,8 +1798,12 @@ static void fence_request_cb (flux_t *h, flux_msg_handler_t *mh,
             goto error;
         }
     }
-    else
-        fence_set_flags (f, fence_get_flags (f) | flags);
+
+    if (fence_get_flags (f) != flags
+        || fence_get_nprocs (f) != nprocs) {
+        errno = EINVAL;
+        goto error;
+    }
 
     if (fence_add_request_copy (f, msg) < 0)
         goto error;