diff --git a/plugins/node.d/postgres_querylength_.in b/plugins/node.d/postgres_querylength_.in
index 873424503..8ad84a97d 100644
--- a/plugins/node.d/postgres_querylength_.in
+++ b/plugins/node.d/postgres_querylength_.in
@@ -65,7 +65,7 @@ my $pg = Munin::Plugin::Pgsql->new(
     info      => 'Most long-running queries and transactions',
     vlabel    => 'Age (seconds)',
     basequery => [
-        "SELECT 'query',COALESCE(max(extract(epoch FROM CURRENT_TIMESTAMP-query_start)),0) FROM pg_stat_activity WHERE (state NOT LIKE 'idle%' AND xact_start IS NOT NULL) %%FILTER%%
+        "SELECT 'query',COALESCE(max(extract(epoch FROM CURRENT_TIMESTAMP-query_start)),0) FROM pg_stat_activity WHERE (backend_type = 'client backend' AND state NOT LIKE 'idle%' AND xact_start IS NOT NULL) %%FILTER%%
                      UNION ALL
                     SELECT 'transaction',COALESCE(max(extract(epoch FROM CURRENT_TIMESTAMP-xact_start)),0) FROM pg_stat_activity WHERE 1=1 %%FILTER%%",
         [