diff --git a/src/plugins/debugger/cdb/bytearrayinputstream.cpp b/src/plugins/debugger/cdb/bytearrayinputstream.cpp
index c7df38e835098d84d2264be2770f1e8737c0f880..2ac8545facc55dda70eb7a1b3963662d326858b0 100644
--- a/src/plugins/debugger/cdb/bytearrayinputstream.cpp
+++ b/src/plugins/debugger/cdb/bytearrayinputstream.cpp
@@ -33,6 +33,8 @@
 
 #include "bytearrayinputstream.h"
 
+#include <ctype.h>
+
 namespace Debugger {
 namespace Internal {