diff --git a/src/google/protobuf/stubs/hash.h b/src/google/protobuf/stubs/hash.h
index 07798bcd9f..822d605013 100644
--- a/src/google/protobuf/stubs/hash.h
+++ b/src/google/protobuf/stubs/hash.h
@@ -48,8 +48,6 @@
 #include <set>
 #endif
 
-#include <ext/hash_map>
-
 namespace google {
 namespace protobuf {