diff --git a/src/challenge-module/challenge-email.cpp b/src/challenge-module/challenge-email.cpp
index cac0084..aec7859 100644
--- a/src/challenge-module/challenge-email.cpp
+++ b/src/challenge-module/challenge-email.cpp
@@ -19,11 +19,8 @@
  */
 
 #include "challenge-email.hpp"
-
-#include <regex>
-
 #include "../ca-module.hpp"
-#include "../logging.hpp"
+#include <regex>
 
 namespace ndn {
 namespace ndncert {