diff --git a/mysql/select_statement.go b/mysql/select_statement.go
index fa6dd9c..8ebab03 100644
--- a/mysql/select_statement.go
+++ b/mysql/select_statement.go
@@ -106,6 +106,7 @@ func (s *selectStatementImpl) DISTINCT() SelectStatement {
 }
 
 func (s *selectStatementImpl) FROM(tables ...ReadableTable) SelectStatement {
+	s.From.Tables = nil
 	for _, table := range tables {
 		s.From.Tables = append(s.From.Tables, table)
 	}
diff --git a/postgres/select_statement.go b/postgres/select_statement.go
index a0d3e27..516ae25 100644
--- a/postgres/select_statement.go
+++ b/postgres/select_statement.go
@@ -109,6 +109,7 @@ func (s *selectStatementImpl) DISTINCT() SelectStatement {
 }
 
 func (s *selectStatementImpl) FROM(tables ...ReadableTable) SelectStatement {
+	s.From.Tables = nil
 	for _, table := range tables {
 		s.From.Tables = append(s.From.Tables, table)
 	}