diff --git a/lib/debug.ml b/lib/debug.ml
index ce2a62e..2c70401 100644
--- a/lib/debug.ml
+++ b/lib/debug.ml
@@ -1,7 +1,7 @@
-let print_dns_header (header : Types.dns_header) =
-  Printf.printf
+let dns_header (header : Types.dns_header) =
+  Printf.sprintf
     "{ id = %d; flags = %d; num_questions = %d; num_answers = %d; num_authorities = %d; \
-     num_additionals = %d }\n"
+     num_additionals = %d }"
     header.id
     header.flags
     header.num_questions
@@ -10,17 +10,17 @@ let print_dns_header (header : Types.dns_header) =
     header.num_additionals
 ;;
 
-let print_dns_question (question : Types.dns_question) =
-  Printf.printf
-    "{ name = '%s'; type_ = %d; class_ = %d }\n"
+let dns_question (question : Types.dns_question) =
+  Printf.sprintf
+    "{ name = '%s'; type_ = %d; class_ = %d }"
     (Bytes.to_string question.name)
     question.type_
     question.class_
 ;;
 
-let print_dns_record (record : Types.dns_record) =
-  Printf.printf
-    "{ name = '%s'; type_ = %d; class_ = %d; ttl = %d; data = '%s' }\n"
+let dns_record (record : Types.dns_record) =
+  Printf.sprintf
+    "{ name = '%s'; type_ = %d; class_ = %d; ttl = %d; data = '%s' }"
     (Bytes.to_string record.name)
     record.type_
     record.class_