diff --git a/wp-includes/category.php b/wp-includes/category.php
index edfc0f5407..56cdbb9d35 100644
--- a/wp-includes/category.php
+++ b/wp-includes/category.php
@@ -169,8 +169,9 @@ function get_category_by_path($category_path, $full_match = true, $output = OBJE
 	$category_paths = '/' . trim($category_path, '/');
 	$leaf_path  = sanitize_title(basename($category_paths));
 	$category_paths = explode('/', $category_paths);
-	foreach($category_paths as $pathdir)
-		$full_path .= ($pathdir!=''?'/':'') . sanitize_title($pathdir);
+	$full_path = '';
+	foreach ( (array) $category_paths as $pathdir )
+		$full_path .= ( $pathdir != '' ? '/' : '' ) . sanitize_title($pathdir);
 
 	$categories = $wpdb->get_results("SELECT cat_ID, category_nicename, category_parent FROM $wpdb->categories WHERE category_nicename = '$leaf_path'");
 
diff --git a/wp-includes/query.php b/wp-includes/query.php
index 92ece54eb8..4a931ec1ca 100644
--- a/wp-includes/query.php
+++ b/wp-includes/query.php
@@ -819,8 +819,9 @@ class WP_Query {
 			$cat_paths = '/' . trim(urldecode($q['category_name']), '/');
 			$q['category_name'] = sanitize_title(basename($cat_paths));
 			$cat_paths = explode('/', $cat_paths);
-			foreach($cat_paths as $pathdir)
-				$cat_path .= ($pathdir!=''?'/':'') . sanitize_title($pathdir);
+			$cat_path = '';
+			foreach ( (array) $cat_paths as $pathdir )
+				$cat_path .= ( $pathdir != '' ? '/' : '' ) . sanitize_title($pathdir);
 
 			//if we don't match the entire hierarchy fallback on just matching the nicename
 			if ( empty($reqcat) )