diff --git a/src/system/Error.hxx b/src/system/Error.hxx
index 056bbd017..5fc697ccb 100644
--- a/src/system/Error.hxx
+++ b/src/system/Error.hxx
@@ -30,7 +30,6 @@
 #ifndef SYSTEM_ERROR_HXX
 #define SYSTEM_ERROR_HXX
 
-#include "util/StringUtil.hxx"
 #include "Compiler.h"
 
 #include <system_error>