diff --git a/src/google/protobuf/text_format.cc b/src/google/protobuf/text_format.cc
index b8ddd086e3..d6298c8c42 100644
--- a/src/google/protobuf/text_format.cc
+++ b/src/google/protobuf/text_format.cc
@@ -42,6 +42,7 @@
 #include <climits>
 #include <cmath>
 #include <limits>
+#include <set>
 #include <string>
 #include <utility>
 #include <vector>