diff --git a/classes/rpc.php b/classes/rpc.php
index e3870aa41..b5cbbbcea 100755
--- a/classes/rpc.php
+++ b/classes/rpc.php
@@ -435,9 +435,8 @@ class RPC extends Handler_Protected {
 				) OR (
 					ttrss_feeds.update_interval > 0
 					AND ttrss_feeds.last_updated < NOW() - CAST((ttrss_feeds.update_interval || ' minutes') AS INTERVAL)
-				) OR ttrss_feeds.last_updated IS NULL
-				OR (
-					ttrss_feeds.update_interval > 0
+				) OR (
+					ttrss_feeds.update_interval >= 0
 					AND (last_updated = '1970-01-01 00:00:00' OR last_updated IS NULL)
 				))";
 		} else {
@@ -447,9 +446,8 @@ class RPC extends Handler_Protected {
 				) OR (
 					ttrss_feeds.update_interval > 0
 					AND ttrss_feeds.last_updated < DATE_SUB(NOW(), INTERVAL ttrss_feeds.update_interval MINUTE)
-				) OR ttrss_feeds.last_updated IS NULL
-				OR (
-					ttrss_feeds.update_interval > 0
+				) OR (
+					ttrss_feeds.update_interval >= 0
 					AND (last_updated = '1970-01-01 00:00:00' OR last_updated IS NULL)
 				))";
 		}
diff --git a/classes/rssutils.php b/classes/rssutils.php
index f2806cf49..3555d6e0b 100755
--- a/classes/rssutils.php
+++ b/classes/rssutils.php
@@ -52,37 +52,31 @@ class RSSUtils {
 			$update_limit_qpart = "AND ((
 					ttrss_feeds.update_interval = 0
 					AND ttrss_user_prefs.value != '-1'
-					AND ttrss_feeds.last_updated < NOW() - CAST((ttrss_user_prefs.value || ' minutes') AS INTERVAL)
+					AND last_updated < NOW() - CAST((ttrss_user_prefs.value || ' minutes') AS INTERVAL)
 				) OR (
 					ttrss_feeds.update_interval > 0
-					AND ttrss_feeds.last_updated < NOW() - CAST((ttrss_feeds.update_interval || ' minutes') AS INTERVAL)
-				) OR (ttrss_feeds.last_updated IS NULL
-					AND ttrss_feeds.update_interval > 0
-					AND ttrss_user_prefs.value != '-1')
-				OR (last_updated = '1970-01-01 00:00:00'
-					AND ttrss_feeds.update_interval > 0
+					AND last_updated < NOW() - CAST((ttrss_feeds.update_interval || ' minutes') AS INTERVAL)
+				) OR ((last_updated = '1970-01-01 00:00:00' OR last_updated IS NULL)
+					AND ttrss_feeds.update_interval >= 0
 					AND ttrss_user_prefs.value != '-1'))";
 		} else {
 			$update_limit_qpart = "AND ((
 					ttrss_feeds.update_interval = 0
 					AND ttrss_user_prefs.value != '-1'
-					AND ttrss_feeds.last_updated < DATE_SUB(NOW(), INTERVAL CONVERT(ttrss_user_prefs.value, SIGNED INTEGER) MINUTE)
+					AND last_updated < DATE_SUB(NOW(), INTERVAL CONVERT(ttrss_user_prefs.value, SIGNED INTEGER) MINUTE)
 				) OR (
 					ttrss_feeds.update_interval > 0
-					AND ttrss_feeds.last_updated < DATE_SUB(NOW(), INTERVAL ttrss_feeds.update_interval MINUTE)
-				) OR (ttrss_feeds.last_updated IS NULL
-					AND ttrss_feeds.update_interval > 0
-					AND ttrss_user_prefs.value != '-1')
-				OR (last_updated = '1970-01-01 00:00:00'
-					AND ttrss_feeds.update_interval > 0
+					AND last_updated < DATE_SUB(NOW(), INTERVAL ttrss_feeds.update_interval MINUTE)
+				) OR ((last_updated = '1970-01-01 00:00:00' OR last_updated IS NULL)
+					AND ttrss_feeds.update_interval >= 0
 					AND ttrss_user_prefs.value != '-1'))";
 		}
 
 		// Test if feed is currently being updated by another process.
 		if (DB_TYPE == "pgsql") {
-			$updstart_thresh_qpart = "AND (ttrss_feeds.last_update_started IS NULL OR ttrss_feeds.last_update_started < NOW() - INTERVAL '10 minutes')";
+			$updstart_thresh_qpart = "AND (last_update_started IS NULL OR last_update_started < NOW() - INTERVAL '10 minutes')";
 		} else {
-			$updstart_thresh_qpart = "AND (ttrss_feeds.last_update_started IS NULL OR ttrss_feeds.last_update_started < DATE_SUB(NOW(), INTERVAL 10 MINUTE))";
+			$updstart_thresh_qpart = "AND (last_update_started IS NULL OR last_update_started < DATE_SUB(NOW(), INTERVAL 10 MINUTE))";
 		}
 
 		$query_limit = $limit ? sprintf("LIMIT %d", $limit) : "";