diff --git a/src/asn1_types/tagged/implicit.rs b/src/asn1_types/tagged/implicit.rs
index ed98b63..5594e49 100644
--- a/src/asn1_types/tagged/implicit.rs
+++ b/src/asn1_types/tagged/implicit.rs
@@ -124,7 +124,7 @@ where
         let inner_len = self.inner.write_der_content(&mut sink)?;
         // XXX X.690 section 8.14.3: if implicing tagging was used [...]:
         // XXX a) the encoding shall be constructed if the base encoding is constructed, and shall be primitive otherwise
-        let constructed = matches!(TAG, 16 | 17);
+        let constructed = matches!(self.inner.tag(), Tag::Sequence | Tag::Set);
         let header = Header::new(class, constructed, self.tag(), Length::Definite(inner_len));
         header.write_der_header(writer).map_err(Into::into)
     }