diff --git a/webapp/sources/rudder/rudder-web/src/main/scala/com/normation/rudder/web/comet/AsyncDeployment.scala b/webapp/sources/rudder/rudder-web/src/main/scala/com/normation/rudder/web/comet/AsyncDeployment.scala
index 68dcd47357c..a367e2fc932 100644
--- a/webapp/sources/rudder/rudder-web/src/main/scala/com/normation/rudder/web/comet/AsyncDeployment.scala
+++ b/webapp/sources/rudder/rudder-web/src/main/scala/com/normation/rudder/web/comet/AsyncDeployment.scala
@@ -239,7 +239,7 @@ class AsyncDeployment extends CometActor with CometListener with Loggable {
   }
 
   private[this] def errorPopup = {
-    <div class="modal fade" tabindex="-1" id="errorDetailsDialog">
+    <div class="modal fade" tabindex="-1" id="errorDetailsDialog" data-bs-backdrop="false">
         <div class="modal-dialog">
             <div class="modal-content">
                 <div class="modal-header">
@@ -267,7 +267,7 @@ class AsyncDeployment extends CometActor with CometListener with Loggable {
   }
 
   private[this] def generatePoliciesPopup = {
-    <div class="modal fade" tabindex="-1" id="generatePoliciesDialog" aria-hidden="true">
+    <div class="modal fade" tabindex="-1" id="generatePoliciesDialog" aria-hidden="true" data-bs-backdrop="false" data-bs-dismiss="modal">
       <div class="modal-dialog">
         <div class="modal-content">
           <div class="modal-header">
diff --git a/webapp/sources/rudder/rudder-web/src/main/scala/com/normation/rudder/web/components/NodeGroupCategoryForm.scala b/webapp/sources/rudder/rudder-web/src/main/scala/com/normation/rudder/web/components/NodeGroupCategoryForm.scala
index b072faff281..f64c5a0d7b2 100644
--- a/webapp/sources/rudder/rudder-web/src/main/scala/com/normation/rudder/web/components/NodeGroupCategoryForm.scala
+++ b/webapp/sources/rudder/rudder-web/src/main/scala/com/normation/rudder/web/components/NodeGroupCategoryForm.scala
@@ -176,7 +176,7 @@ class NodeGroupCategoryForm(
 
     if (parentCategory.isDefined && _nodeGroupCategory.children.isEmpty && _nodeGroupCategory.items.isEmpty) {
       val popupContent = {
-           <div class="modal-dialog">
+        <div class="modal-dialog">
              <div class="modal-content">
                <div class="modal-header">
                  <h5 class="modal-title text-start">
diff --git a/webapp/sources/rudder/rudder-web/src/main/scala/com/normation/rudder/web/components/popup/CreateOrUpdateGlobalParameterPopup.scala b/webapp/sources/rudder/rudder-web/src/main/scala/com/normation/rudder/web/components/popup/CreateOrUpdateGlobalParameterPopup.scala
index 76ffc84caa0..71d3bd300d2 100644
--- a/webapp/sources/rudder/rudder-web/src/main/scala/com/normation/rudder/web/components/popup/CreateOrUpdateGlobalParameterPopup.scala
+++ b/webapp/sources/rudder/rudder-web/src/main/scala/com/normation/rudder/web/components/popup/CreateOrUpdateGlobalParameterPopup.scala
@@ -402,7 +402,7 @@ class CreateOrUpdateGlobalParameterPopup(
   }
   private[this] def formXml(): NodeSeq = {
     SHtml.ajaxForm(
-    <div class="modal-dialog">
+      <div class="modal-dialog">
         <div class="modal-content">
             <div class="modal-header">
               <h5 class="modal-title" id="title">Here come title</h5>
diff --git a/webapp/sources/rudder/rudder-web/src/main/scala/com/normation/rudder/web/snippet/administration/TechniqueLibraryManagement.scala b/webapp/sources/rudder/rudder-web/src/main/scala/com/normation/rudder/web/snippet/administration/TechniqueLibraryManagement.scala
index f1888a931fa..ebf7db16d5e 100644
--- a/webapp/sources/rudder/rudder-web/src/main/scala/com/normation/rudder/web/snippet/administration/TechniqueLibraryManagement.scala
+++ b/webapp/sources/rudder/rudder-web/src/main/scala/com/normation/rudder/web/snippet/administration/TechniqueLibraryManagement.scala
@@ -842,7 +842,9 @@ class TechniqueLibraryManagement extends DispatchSnippet with Loggable {
     setCreationPopup
 
     // update UI
-    SetHtml("createActiveTechniquesCategoryContainer", createPopup) & JsRaw("""initBsModal("createActiveTechniqueCategoryPopup")""")
+    SetHtml("createActiveTechniquesCategoryContainer", createPopup) & JsRaw(
+      """initBsModal("createActiveTechniqueCategoryPopup")"""
+    )
 
   }
 
diff --git a/webapp/sources/rudder/rudder-web/src/main/style/rudder/rudder-menu.scss b/webapp/sources/rudder/rudder-web/src/main/style/rudder/rudder-menu.scss
index 33bc115d9fb..30c04535753 100644
--- a/webapp/sources/rudder/rudder-web/src/main/style/rudder/rudder-menu.scss
+++ b/webapp/sources/rudder/rudder-web/src/main/style/rudder/rudder-menu.scss
@@ -61,6 +61,14 @@ $navbar-hover-color : #F4F4F4;
   background-color: #fff;
   box-shadow: 4px 4px 10px #dce3efb0;
 }
+
+.modal-open {
+  .main-header > .navbar,
+  .main-header > .logo{
+    z-index: -1;
+  }
+}
+
 .main-header .form-control::-moz-placeholder {
   color: #36474eaa;
   opacity: 1
@@ -771,7 +779,7 @@ header.main-header .logo-lg img{
  }
  aside.main-sidebar.fixed {
   position:fixed;
-  z-index: 1030;
+  z-index: 1020;
   height: calc(100% - 50px);
   min-height: calc(100% - 50px);
   margin-top: 50px;
@@ -1182,4 +1190,11 @@ header.main-header .logo-lg img{
 }
 .content-wrapper label > .icon-info:hover{
   color: #286090;
+}
+
+// MODALS
+
+.modal.fade.show[data-bs-backdrop="false"] {
+  background-color: rgba(0,0,0,0.5);
+  position: fixed;
 }
\ No newline at end of file