diff --git a/sqlx-core/src/postgres/type_info.rs b/sqlx-core/src/postgres/type_info.rs
index b5e5f98ea7..37c018f798 100644
--- a/sqlx-core/src/postgres/type_info.rs
+++ b/sqlx-core/src/postgres/type_info.rs
@@ -742,8 +742,11 @@ impl PgType {
 
             PgType::Custom(ty) => &ty.kind,
 
-            PgType::DeclareWithOid(_) | PgType::DeclareWithName(_) => {
-                unreachable!("(bug) use of unresolved type declaration [kind]")
+            PgType::DeclareWithOid(oid) => {
+                unreachable!("(bug) use of unresolved type declaration [oid={}]", oid);
+            }
+            PgType::DeclareWithName(name) => {
+                unreachable!("(bug) use of unresolved type declaration [name={}]", name);
             }
         }
     }