diff --git a/wp-includes/functions.php b/wp-includes/functions.php
index 2e522c2e2..eb6654747 100644
--- a/wp-includes/functions.php
+++ b/wp-includes/functions.php
@@ -4278,9 +4278,9 @@ function _wp_meta_sql( $queries, $primary_table, $primary_id_column, $meta_table
 	$where = '';
 	$i = 0;
 	foreach ( $queries as $q ) {
-		$meta_key = isset( $q['meta_key'] ) ? trim( $q['meta_key'] ) : '';
-		$meta_value = isset( $q['meta_value'] ) ? trim( $q['meta_value'] ) : '';
-		$meta_compare = isset( $q['meta_compare'] ) ? $q['meta_compare'] : '=';
+		$meta_key = isset( $q['key'] ) ? trim( $q['key'] ) : '';
+		$meta_value = isset( $q['value'] ) ? trim( $q['value'] ) : '';
+		$meta_compare = isset( $q['compare'] ) ? $q['compare'] : '=';
 
 		if ( !in_array( $meta_compare, array( '=', '!=', '>', '>=', '<', '<=', 'like' ) ) )
 			$meta_compare = '=';
diff --git a/wp-includes/query.php b/wp-includes/query.php
index 02d5d6043..ed2e000ca 100644
--- a/wp-includes/query.php
+++ b/wp-includes/query.php
@@ -1393,10 +1393,15 @@ class WP_Query {
 				$this->meta_query = $qv['meta_query'];
 			}
 
-			$meta_query = wp_array_slice_assoc( $qv, array( 'meta_key', 'meta_value', 'meta_compare' ) );
+			$meta_query = array();
+			foreach ( array( 'key', 'value', 'compare' ) as $key ) {
+				if ( !empty( $qv[ "meta_$key" ] ) )
+					$meta_query[ $key ] = $qv[ "meta_$key" ];
+			}
 
-			if ( !empty( $meta_query ) )
+			if ( !empty( $meta_query ) ) {
 				$this->meta_query[] = $meta_query;
+			}
 
 			if ( empty($qv['author']) || ($qv['author'] == '0') ) {
 				$this->is_author = false;
diff --git a/wp-includes/user.php b/wp-includes/user.php
index db7b561a7..af0e42fcc 100644
--- a/wp-includes/user.php
+++ b/wp-includes/user.php
@@ -451,17 +451,25 @@ class WP_User_Query {
 
 		if ( $blog_id ) {
 			$cap_meta_query = array();
-			$cap_meta_query['meta_key'] = $wpdb->get_blog_prefix( $blog_id ) . 'capabilities';
+			$cap_meta_query['key'] = $wpdb->get_blog_prefix( $blog_id ) . 'capabilities';
 
 			if ( $role ) {
-				$cap_meta_query['meta_value'] = $role;
-				$cap_meta_query['meta_compare'] = 'like';
+				$cap_meta_query['value'] = $role;
+				$cap_meta_query['compare'] = 'like';
 			}
 
 			$meta_queries[] = $cap_meta_query;
 		}
 
-		$meta_queries[] = wp_array_slice_assoc( $qv, array( 'meta_key', 'meta_value', 'meta_compare' ) );
+		$meta_query = array();
+		foreach ( array( 'key', 'value', 'compare' ) as $key ) {
+			if ( !empty( $qv[ "meta_$key" ] ) )
+				$meta_query[ $key ] = $qv[ "meta_$key" ];
+		}
+
+		if ( !empty( $meta_query ) ) {
+			$meta_queries[] = $meta_query;
+		}
 
 		list( $meta_join, $meta_where ) = _wp_meta_sql( $meta_queries, $wpdb->users, 'ID', $wpdb->usermeta, 'user_id' );
 		$this->query_from .= $meta_join;