diff --git a/src/string.cc b/src/string.cc
index 6a1fda55..ef115b2b 100644
--- a/src/string.cc
+++ b/src/string.cc
@@ -4,6 +4,8 @@
 #include "containers.hh"
 #include "utf8_iterator.hh"
 
+#include <cstdio>
+
 namespace Kakoune
 {