diff --git a/src/wp-admin/css/forms.css b/src/wp-admin/css/forms.css
index 151b60aa77467..4d55c155cfe1c 100644
--- a/src/wp-admin/css/forms.css
+++ b/src/wp-admin/css/forms.css
@@ -727,7 +727,6 @@ p.search-box {
 	clear: left;
 }
 
-.search-box input[name="s"],
 .tablenav .search-plugins input[name="s"],
 .tagsdiv .newtag {
 	float: left;
@@ -1653,11 +1652,15 @@ table.form-table td .updated p {
 	}
 
 	p.search-box input[name="s"] {
-		float: none;
 		width: 100%;
+		float: none;
 		margin-bottom: 10px;
 		vertical-align: middle;
 	}
+	.js.plugins-php .search-box .wp-filter-search {
+		width: 100%;
+		margin-bottom: 0;
+	}
 
 	p.search-box input[type="submit"] {
 		margin-bottom: 10px;
diff --git a/src/wp-admin/css/themes.css b/src/wp-admin/css/themes.css
index 7d4bb848a129a..326531528ee62 100644
--- a/src/wp-admin/css/themes.css
+++ b/src/wp-admin/css/themes.css
@@ -961,12 +961,7 @@ body.folded .theme-browser ~ .theme-overlay .theme-wrap {
 	}
 
 	.themes-php .wp-filter-search {
-		float: none;
-		clear: both;
-		left: 0;
-		right: 0;
 		width: 100%;
-		max-width: 280px;
 	}
 
 	.theme-install-php .wp-filter p.search-box {