diff --git a/src/util/StringFormatter.cc b/src/util/StringFormatter.cc
index 0b183ac..b361c2d 100644
--- a/src/util/StringFormatter.cc
+++ b/src/util/StringFormatter.cc
@@ -1,4 +1,6 @@
 #include <cstdarg>
+#include <algorithm>
+#include <cassert>
 
 #include "StringFormatter.h"
 
diff --git a/src/util/StringFormatter.h b/src/util/StringFormatter.h
index 048a30f..2d34126 100644
--- a/src/util/StringFormatter.h
+++ b/src/util/StringFormatter.h
@@ -8,6 +8,9 @@
 #ifndef STRINGFORMATTER_H__
 #define STRINGFORMATTER_H__
 
+#include <vector>
+#include <cstdio>
+
 namespace pdf2htmlEX {
 
 class StringFormatter