diff --git a/conversejs/custom/shared/styles/_variables.scss b/conversejs/custom/shared/styles/_variables.scss
index 0e72c80b..efa1afb7 100644
--- a/conversejs/custom/shared/styles/_variables.scss
+++ b/conversejs/custom/shared/styles/_variables.scss
@@ -17,6 +17,18 @@ body.converse-embedded {
   --livechat-transparent: rgba(0 0 0 / 0%);
 }
 
+body.converse-embedded {
+  .conversejs .modal {
+    // modal z-index = use same z-index as Peertube (see Peertube _variables.scss)
+    z-index: 19000;
+  }
+
+  .modal-backdrop {
+    // must be just under .modal.
+    z-index: 18999;
+  }
+}
+
 /* Chat embedded in a full client page. */
 .livechat-embed-fullpage {
   converse-root {