--- ./Source/Common/gdcmString.h.orig	2019-02-25 17:28:26.424232122 +0000
+++ ./Source/Common/gdcmString.h	2019-02-25 17:28:57.986168143 +0000
@@ -27,7 +27,7 @@ namespace gdcm
  *      TMaxLength is only a hint. Noone actually respect the max length
  *      TPadChar is the string padding (0 or space)
  */
-template <char TDelimiter = '\\', unsigned int TMaxLength = 64, char TPadChar = ' '>
+template <signed char TDelimiter = '\\', unsigned int TMaxLength = 64, signed char TPadChar = ' '>
 class /*GDCM_EXPORT*/ String : public std::string /* PLEASE do not export me */
 {
   // UI wants \0 for pad character, while ASCII ones wants space char... do not allow anything else