diff --git a/src/gn/escape.h b/src/gn/escape.h
index 57a723f..c46d42d 100644
--- a/src/gn/escape.h
+++ b/src/gn/escape.h
@@ -7,6 +7,7 @@
 
 #include <iosfwd>
 #include <string_view>
+#include <string>
 
 enum EscapingMode {
   // No escaping.