diff -Nrup a/lib/BlockArray.cpp b/lib/BlockArray.cpp
--- a/lib/BlockArray.cpp	2019-02-25 15:13:12.000000000 -0700
+++ b/lib/BlockArray.cpp	2019-09-23 12:39:03.081229222 -0600
@@ -31,6 +31,7 @@
 #include <sys/param.h>
 #include <unistd.h>
 #include <stdio.h>
+#include <cwctype>
 
 
 using namespace Konsole;
diff -Nrup a/lib/TerminalCharacterDecoder.cpp b/lib/TerminalCharacterDecoder.cpp
--- a/lib/TerminalCharacterDecoder.cpp	2019-02-25 15:13:12.000000000 -0700
+++ b/lib/TerminalCharacterDecoder.cpp	2019-09-23 12:40:07.091844859 -0600
@@ -31,6 +31,8 @@
 // Konsole
 #include "konsole_wcwidth.h"
 
+#include <cwctype>
+
 using namespace Konsole;
 PlainTextDecoder::PlainTextDecoder()
  : _output(0)
diff -Nrup a/lib/TerminalDisplay.cpp b/lib/TerminalDisplay.cpp
--- a/lib/TerminalDisplay.cpp	2019-02-25 15:13:12.000000000 -0700
+++ b/lib/TerminalDisplay.cpp	2019-09-23 12:40:39.726650013 -0600
@@ -62,6 +62,7 @@
 #include "konsole_wcwidth.h"
 #include "ScreenWindow.h"
 #include "TerminalCharacterDecoder.h"
+#include <cwctype>
 
 using namespace Konsole;