diff --git a/include/string/encoding.h b/include/string/encoding.h
index baef8b487..5b6c3396c 100644
--- a/include/string/encoding.h
+++ b/include/string/encoding.h
@@ -9,6 +9,7 @@
 #ifndef CPPCOMMON_STRING_ENCODING_H
 #define CPPCOMMON_STRING_ENCODING_H
 
+#include <cstdint>
 #include <string>
 
 namespace CppCommon {
diff --git a/include/string/string_utils.h b/include/string/string_utils.h
index 227dbb9f3..a47f4a55f 100644
--- a/include/string/string_utils.h
+++ b/include/string/string_utils.h
@@ -11,6 +11,7 @@
 
 #include <algorithm>
 #include <cctype>
+#include <cstdint>
 #include <sstream>
 #include <string>
 #include <vector>