diff --git a/Build/Resources/Public/Less/TYPO3/_element_tceforms.less b/Build/Resources/Public/Less/TYPO3/_element_tceforms.less
index 7d29f7b11d87f81f206eef29861e87bcb0d3cb26..3d40b63b647eb2dfed2f7128bfe6c9b814a45096 100644
--- a/Build/Resources/Public/Less/TYPO3/_element_tceforms.less
+++ b/Build/Resources/Public/Less/TYPO3/_element_tceforms.less
@@ -241,6 +241,11 @@ div.t3-form-field-container:first-child .t3-form-field-label-flex {
 		filter: alpha(opacity=50);
 	}
 }
+// z-index must be higher as .t3-form-field-disable z-index
+// this is required for the eval=null field checkbox
+.t3-form-field-eval-null-checkbox {
+	z-index: 9000;
+}
 .t3-form-palette-field-label {
 	text-indent: 2px;
 }
diff --git a/typo3/sysext/backend/Classes/Form/Container/SingleFieldContainer.php b/typo3/sysext/backend/Classes/Form/Container/SingleFieldContainer.php
index c65f8622f5ee8619d2a41bd7327db969035f17b8..461467fdd36f5a00c2121e9a154963de822703e8 100644
--- a/typo3/sysext/backend/Classes/Form/Container/SingleFieldContainer.php
+++ b/typo3/sysext/backend/Classes/Form/Container/SingleFieldContainer.php
@@ -226,13 +226,13 @@ class SingleFieldContainer extends AbstractContainer
             $nullValueWrap = array();
             $nullValueWrap[] = '<div class="' . implode(' ', $fieldItemClasses) . '">';
             $nullValueWrap[] =    '<div class="t3-form-field-disable"></div>';
-            $nullValueWrap[] =    '<div class="checkbox">';
+            $nullValueWrap[] =    '<div class="checkbox t3-form-field-eval-null-checkbox">';
             $nullValueWrap[] =        '<label>';
             $nullValueWrap[] =            '<input type="hidden"' . $nullControlNameAttribute . ' value="0" />';
             $nullValueWrap[] =            '<input type="checkbox"' . $nullControlNameAttribute . ' value="1" onchange="' . $onChange . '"' . $checked . ' /> &nbsp;';
             $nullValueWrap[] =        '</label>';
-            $nullValueWrap[] =        $html;
             $nullValueWrap[] =    '</div>';
+            $nullValueWrap[] =    $html;
             $nullValueWrap[] = '</div>';
 
             $html = implode(LF, $nullValueWrap);
diff --git a/typo3/sysext/backend/Resources/Public/Css/backend.css b/typo3/sysext/backend/Resources/Public/Css/backend.css
index 5db0872c5dab547d5f508ac843302ba080e369dd..792f85d034bbc9501b3e1265ef68c678614df44e 100644
--- a/typo3/sysext/backend/Resources/Public/Css/backend.css
+++ b/typo3/sysext/backend/Resources/Public/Css/backend.css
@@ -10585,6 +10585,9 @@ div.t3-form-field-container:first-child .t3-form-field-label-flex {
   opacity: 0.5;
   filter: alpha(opacity=50);
 }
+.t3-form-field-eval-null-checkbox {
+  z-index: 9000;
+}
 .t3-form-palette-field-label {
   text-indent: 2px;
 }