diff --git a/src/system/Error.hxx b/src/system/Error.hxx
index 5a10b6844..7f862a0ee 100644
--- a/src/system/Error.hxx
+++ b/src/system/Error.hxx
@@ -111,14 +111,8 @@ static inline std::system_error
 FormatErrno(int code, const char *fmt, Args&&... args)
 {
 	char buffer[512];
-	const auto end = buffer + sizeof(buffer);
-	size_t length = snprintf(buffer, sizeof(buffer) - 128,
-				 fmt, std::forward<Args>(args)...);
-	char *p = buffer + length;
-	*p++ = ':';
-	*p++ = ' ';
-
-	CopyString(p, strerror(code), end - p);
+	snprintf(buffer, sizeof(buffer),
+		 fmt, std::forward<Args>(args)...);
 	return MakeErrno(code, buffer);
 }