diff --git a/parser.go b/parser.go
index bd1cc1303..9788bdcfd 100644
--- a/parser.go
+++ b/parser.go
@@ -9898,8 +9898,8 @@ yynewstate:
 			}
 			if yyS[yypt-0].item != nil {
 				if sw, ok := (yyS[yypt-0].item.(*ast.StreamWindowSpec)); ok {
-				} else {
 					st.StreamWindowSpec = sw
+				} else {
 					st.WindowSpecs = (yyS[yypt-0].item.([]ast.WindowSpec))
 				}
 			}
diff --git a/parser.y b/parser.y
index 70c9c4177..bfc821344 100644
--- a/parser.y
+++ b/parser.y
@@ -4538,9 +4538,9 @@ SelectStmtFromTable:
 		}
 		if $7 != nil {
 		    if sw, ok := ($7.(*ast.StreamWindowSpec)); ok {
+		        st.StreamWindowSpec = sw
 		    } else {
-		    st.StreamWindowSpec = sw
-		    st.WindowSpecs = ($7.([]ast.WindowSpec))
+		        st.WindowSpecs = ($7.([]ast.WindowSpec))
 		    }
 		}
 		$$ = st
diff --git a/parser_test.go b/parser_test.go
index 71541e5a5..d3f9ef6bd 100644
--- a/parser_test.go
+++ b/parser_test.go
@@ -2557,6 +2557,7 @@ func (s *testParserSuite) TestWindowFunctions(c *C) {
 		{`SELECT FIRST_VALUE(year) OVER (w ORDER BY year ASC) AS first FROM sales WINDOW w AS (PARTITION BY country);`, true},
 		{`SELECT RANK() OVER w1 FROM t WINDOW w1 AS (w2), w2 AS (), w3 AS (w1);`, true},
 		{`SELECT RANK() OVER w1 FROM t WINDOW w1 AS (w2), w2 AS (w3), w3 AS (w1);`, true},
+		{`SELECT COUNT(*) FROM st group by a window tumbling ( size 5 SECOND);`, true},
 	}
 	s.enableWindowFunc = true
 	s.RunTest(c, table)