diff --git a/d2parser/parse.go b/d2parser/parse.go
index 84d032a58..3a615cc36 100644
--- a/d2parser/parse.go
+++ b/d2parser/parse.go
@@ -1185,6 +1185,7 @@ func (p *parser) parseUnquotedString(inKey bool) (s *d2ast.UnquotedString) {
 					rawv := rawb.String()
 					s.Value = append(s.Value, d2ast.InterpolationBox{String: &sv, StringRaw: &rawv})
 					sb.Reset()
+					rawb.Reset()
 				}
 				s.Value = append(s.Value, d2ast.InterpolationBox{Substitution: subst})
 				continue