diff --git a/src/ELF/Binary.cpp b/src/ELF/Binary.cpp
index d28e31f..b417f8b 100644
--- a/src/ELF/Binary.cpp
+++ b/src/ELF/Binary.cpp
@@ -18,6 +18,7 @@
 #include <numeric>
 #include <sstream>
 #include <map>
+#include <cctype>
 
 #include "LIEF/DWARF/enums.hpp"