diff --git a/pkg/sql/scanner/scan.go b/pkg/sql/scanner/scan.go
index a4cb630e8b88..2b1e53876f70 100644
--- a/pkg/sql/scanner/scan.go
+++ b/pkg/sql/scanner/scan.go
@@ -98,6 +98,7 @@ func (s *Scanner) Init(str string) {
 // where we reuse a Scanner).
 func (s *Scanner) Cleanup() {
 	s.bytesPrealloc = nil
+	s.Comments = nil
 }
 
 func (s *Scanner) allocBytes(length int) []byte {